PHILADELPHIA — Technology developed to jam cellphones during the Iraq War may be getting deployed against journalists reporting on protests against the political establishment in the United States.

While police and government surveillance of protests, including monitoring of cellphone use, is well-documented, efforts to block signals at protests remains an oft-repeated, but never proven, rumor.

It may be impossible to definitively prove that authorities are using cellphone “jamming” technology, but journalists working with both mainstream and independent media reported unusual difficulties accessing the internet during recent protests at the gates of the Democratic National Convention, consistent with the effects this very real technology could have.

During the protests outside the DNC, which I covered for MintPress News, I experienced this personally, with my internet connection behaving suspiciously near the convention’s security fences and entrance gates, often abruptly blocking my tweets and other communication. The same was true for every other journalist I spoke with who covered the protests.

“It’s scary for me as a journalist because that’s how state suppression of events occurs,” said Desiree Kane, a freelance journalist and direct action organizer who covered the Republican National Convention for MintPress and also took part in protests in Philadelphia.

“That’s exactly how it happens is you block communications of what might be going down,” she added.

‘By Tuesday night, everybody noticed’

Jon Ziegler, an experienced citizen journalist, spoke with me on July 28, the final day of the DNC. He recalled his shock at the obvious disruption to his service during the previous days’ events.

Ziegler, who livestreams on several social networks under the name @Rebelutionary_Z and supports his work through crowdfunding, has been covering protests and activism like that which occurred in Philadelphia since the early days of the national Occupy Wall Street movement in 2011.

“I’ve streamed all over the country. I’ve streamed in big cities and small towns, large crowds, any type of situation you can imagine,” he said.

He said it’s important to distinguish between normal, everyday disruptions — for example, a temporary loss of signal caused by tall buildings during protests in downtown Philadelphia — and the seemingly deliberate interruptions journalists experienced near the Wells Fargo Center, the site of the DNC in South Philadelphia.

“You have some data reception issues for here and there, but they always will correct themselves, and I can usually do some measures to get back up live very quickly.”

Just before traveling to the convention, Ziegler upgraded his livestreaming equipment so that he could access a portable WiFi hotspot through Verizon and another phone using AT&T. This would allow him to alternate between the two networks at a moment’s notice. In addition, he uses multiple livestreaming apps connected to his Twitter account, allowing him to switch apps during interruptions.

“Here in Philadelphia, I’ve actually had the most options for connecting to the internet and streaming services that I’ve ever had in the four years that I’ve been doing this, and yet I’ve encountered the most problems, especially down by the gate of the DNC, than ever before.”

Connection problems occurred with varying degrees of severity throughout the week of the DNC, and it was a frequent topic of conversation among journalists. “Monday night we we were talking about how it was strange, but by Tuesday night, everybody kind of noticed, ‘Wait a minute, this isn’t right,’” Ziegler said.

“At some points, even just trying to send tweets out was impossible,” he continued. “Heaven forbid you try to upload a video or photo, but sometimes even text tweets are impossible to get out.”

Regardless of the network carrier and the livestreaming app he used, Ziegler was often stymied.

“Monday, Tuesday, and Wednesday, the second we even get close to those gates my livestream gets glitchy, or drops out completely, or you just can’t connect to the internet at all.”

Even mainstream media journalists experienced jamming at DNC

My experiences matched Ziegler’s. For the first time in years, I sometimes had to rely on Twitter’s antiquated text message gateway to send out the simplest of tweets using SMS messages. Using the Twitter app, even non-multimedia tweets sometimes took over an hour to publish.

Some of the worst interruptions came on the night of Wednesday July 27. Because it was the night President Barack Obama spoke to the convention, the fence was guarded by the Secret Service as well as local, state and federal police.

The already troubling bandwidth problems peaked during some of the week’s most intense protesting, just as activists briefly broke through the security fence, and social networks and livestreaming services remained largely inaccessible for the rest of the night.

Kane found that her cellphone service disappeared just as she filmed a group of armored riot police briefly deployed to the disruption outside of the DNC.

Spooked by the service interruption and the sudden increase in tensions between protesters and police, she said, “I walked away maybe five blocks back to my car,” where she found her service returned, allowing her to upload her video.

“Even mainstream journalists were starting to question whether we had some kind of jamming,” Ziegler told me.

I spoke briefly with Myles Miller, a reporter for New York’s PIX11 News, who expressed frustration at his inability to share video of events as they unfolded, or even immediately after.

.@PIX11News' cameras were rolling as protestors clashed with police outside the @DemConvention pic.twitter.com/IbluFI9wAE — Myles Miller (@MylesMill) July 28, 2016

Unicorn Riot, another crowdfunded team of journalists, described similar bandwidth issues. And a staff member from Fusion, part of a group of representatives of the online news site at the protests, told me that although they were equipped with specialized livestreaming equipment which linked five SIM cards — the equivalent of having five mobile phones working together, across multiple cellular networks — the team was still unable to get a signal on Wednesday night after the fence was breached.

On July 28, the convention’s final night, I found the ability to share photos and videos was slightly improved — tweets uploaded slowly rather than not at all. But when protesters again gathered near the fence, both Ziegler and I noticed that our signals cut out entirely, exactly when police moved to push the protest away with their bicycles.

And, later that night, Joanne Leon, a citizen journalist, reported to me via Twitter that she’d watched every user in the area on Periscope, a popular livestreaming app, simultaneously “disappear” from the internet.

Periscope streams on perimeter of DNC conv all stopped at once.#DemsInPhilly pic.twitter.com/oCfa3xxHbD — Joanne Leon (@joanneleon) July 29, 2016

Developed in Iraq, deployed in Philadelphia?

The use of cellphone jamming technology to protect the president, as may have occurred on July 27 during the convention, is an open secret: occasionally reported on, but rarely discussed. The Washington Post reported in 2009:

“As President Obama’s motorcade rolled down Pennsylvania Avenue on Inauguration Day, federal authorities deployed a closely held law enforcement tool: equipment that can jam cellphones and other wireless devices to foil remote-controlled bombs, sources said.

It is an increasingly common technology, with federal agencies expanding its use as state and local agencies are pushing for permission to do the same. … But jamming remains strictly illegal for state and local agencies. Federal officials barely acknowledge that they use it inside the United States, and the few federal agencies that can jam signals usually must seek a legal waiver first.”

But while illegal for them to use in most cases in this manner, police do have access to technology that can interfere with cell signals, deliberately or otherwise. “Stingrays,” the controversial devices which let police monitor cellphone signals by masquerading as a cell tower, are routinely used to maintain lists of activists who attend protests. But they can interfere with signals, too.

Last year, the ACLU forced the federal government to admit to the Stingray’s capability to block signals as well as monitor them, sometimes even interfering with innocent bystanders uninvolved with protests or other events that involve police.

“We think the fact that stingrays block or drop calls of cell phone users in the vicinity should be of concern to cell service providers, the FCC, and ordinary people,” Nate Wessler, staff attorney with the ACLU’s Speech, Privacy, and Technology Project, said in a March 2015 interview with WIRED magazine. “If an emergency or important/urgent call (to a doctor, a loved one, etc.) is blocked or dropped by this technology, that’s a serious problem.”

#FBISkySpies, DHS, USAF, Pennsylvania State Police conducting aerial surveillance simultaneously over #DNCinPHL. pic.twitter.com/rHPBZG5SZl — North Star Post (@NStarPost) July 25, 2016

Police and the U.S. government are famously reticent to admit to their use of this technology or its capabilities, even once, in 2014, going so far as to seize court records to keep them out of the hands of the ACLU. Harris Corporation, the manufacturer of the Stingray, is even known to have police and other law enforcement agencies sign nondisclosure agreements, legally binding them from revealing details of the technology and its usage.

And with multiple law enforcement agencies known to be engaging in surveillance activities in Philadelphia during the convention, it may be impossible to determine who was responsible. Derrick Broze, writing in an April 2015 MintPress investigation, suggested:

“The federal government, local police departments and the Harris Corporation are participating in a coordinated effort to keep the public in the dark about the full capabilities of cell site simulator surveillance devices, also known as Stingrays.”

It is worth noting that while greater attention has been paid to law enforcement’s use of large-scale military equipment like armored vehicles, cellphone jamming is another example of wartime technology brought home for domestic use. During the Iraq War, cellphone jammers known as Warlocks, were a highly secretive device designed to block the detonation of remote-control bombs.

‘It doesn’t help me feel safe’

While journalists may be the most outspoken targets of cellphone jamming, protesters facing arrest or police brutality are at higher risk.

Desiree Kane, the freelance journalist who attended both the RNC and DNC, is also an experienced protest organizer. She agreed that jamming technology endangers activists, in addition to threatening their First Amendment rights.

“Medics might be watching Twitter to see if they need to deploy other people,” she said. “There’s a lot that depends on our communications.”

But she also emphasized the importance of smartphones and social media to press freedom. “Twitter for journalists is critical,” she noted, highlighting the social media platform’s importance for reporting breaking news.

It’s hard not to be concerned at the expanding use of this technology, especially as the government pushes for access to an “internet kill switch” and corporate players like Apple develop blocks of their own. The potential uses for the technology during future unrest or mass protests are troubling.

“When you take away that kind of tool when things are going down, it doesn’t help me feel safe,” Kane concluded.