For the better part of a day, KrebsOnSecurity, arguably the world's most intrepid source of security news, has been silenced, presumably by a handful of individuals who didn't like a recent series of exposés reporter Brian Krebs wrote. The incident, and the record-breaking data assault that brought it on, open a troubling new chapter in the short history of the Internet.

The crippling distributed denial-of-service attacks started shortly after Krebs published stories stemming from the hack of a DDoS-for-hire service known as vDOS. The first article analyzed leaked data that identified some of the previously anonymous people closely tied to vDOS. It documented how they took in more than $600,000 in two years by knocking other sites offline. A few days later, Krebs ran a follow-up piece detailing the arrests of two men who allegedly ran the service. A third post in the series is here.

On Thursday morning, exactly two weeks after Krebs published his first post, he reported that a sustained attack was bombarding his site with as much as 620 gigabits per second of junk data. That staggering amount of data is among the biggest ever recorded. Krebs was able to stay online thanks to the generosity of Akamai, a network provider that supplied DDoS mitigation services to him for free. The attack showed no signs of waning as the day wore on. Some indications suggest it may have grown stronger. At 4 pm, Akamai gave Krebs two hours' notice that it would no longer assume the considerable cost of defending KrebsOnSecurity. Krebs opted to shut down the site to prevent collateral damage hitting his service provider and its customers.

"It's hard to imagine a stronger form of censorship than these DDoS attacks because if nobody wants to take you on then that's pretty effective censorship," Krebs told Ars on Friday. "I've had a couple of big companies offer and then think better of offering to help me. That's been frustrating."

Thanks, Internet of things

Until recently, a DDoS attack in excess of 600Gb was nearly impossible for all but the most sophisticated and powerful actors to carry out. In 2013, attacks against anti-spam organization Spamhaus generated headlines because the 300Gb torrents were coming uncomfortably close to Internet-threatening size . The assault against KrebsOnSecurity represents a much greater threat for at least two reasons. First, it's twice the size. Second and more significant, unlike the Spamhaus attacks, the staggering volume of bandwidth doesn't rely on misconfigured domain name system servers which, in the big picture, can be remedied with relative ease.

Instead, the attacks against KrebsOnSecurity harness so-called Internet-of-things devices—think home routers, webcams, digital video recorders, and other everyday appliances that have Internet capabilities built into them. Manufacturers design these devices to be as inexpensive and easy-to-use as possible. Consumers often have little technical skill. As a result, the devices frequently come with bug-ridden firmware that never gets updated and easy-to-guess login credentials that never get changed. Their lax security and always-connected status makes the devices easy to remotely commandeer by people who turn them into digital cannons that spray the Internet with shrapnel. On Thursday, security firm Symantec cataloged 11 different families of IoT malware that do just that.

"The current IoT threat landscape shows that it does not require much to exploit an embedded device," Symantec researchers wrote in the report, which was headlined "IoT devices being increasingly used for DDoS attacks." "While we have come across several malware variants exploiting device vulnerabilities—such as Shellshock or the flaw in Ubiquiti routers—the majority of the threats simply take advantage of weak built-in defenses and default password configurations in embedded devices."

The growing supply of IoT malware is creating a tipping point in the denial-of-service domain that's giving relatively unsophisticated actors capabilities that were once reserved only for the most elite of attackers. And that, in turn, represents a threat to the Internet as we know it.

"The biggest threats as far as I'm concerned in terms of censorship come from these ginormous weapons these guys are building," Krebs said. "The idea that tools that used to be exclusively in the hands of nation states are now in the hands of individual actors, it's kind of like the specter of a James Bond movie."

Krebs said he has explored the possibility of retaining a DDoS mitigation service, but he found that the cost—somewhere between $100,000 and $200,000 per year for the type of always-on protection he needs against high-bandwidth attacks—is more than he can afford. For the past four years, he received pro bono help from Prolexic, which was later acquired by Akamai. Over that time, the service has defended KrebsOnSecurity against what he estimates are hundreds of attacks. The latest round has brought that relationship to an end. Krebs said he hopes to be back online later Friday with the help of a service he declined to discuss on the record. Still, he said, he's not sure how long the new arrangement will last.

Of course, if a ragtag band of quasi-hackers can disrupt KrebsOnSecurity, they can disrupt plenty of other sites, too. And this should concern not just the Googles, Apples, and Microsofts of the world but their everyday users as well. Krebs said the threat "screams out" for the kind of industry-wide collaboration that's come together to counter previous threats, including the DNS spoofing bug researcher Dan Kaminsky disclosed in 2008, the Conficker worm that infected huge swaths of the Internet the same year, or the GameOver botnet from last year. Sadly, Krebs said he sees no signs of such cooperation now.

"Free speech in the age of the Internet is not really free," he said. "We're long overdue to treat this threat with a lot more urgency. Unfortunately, I just don't see that happening right now."

Story corrected to change gigabytes to gigabits.