Eli Martinez was in bed last Thursday morning when agents showed up at his home in the northwest suburbs of Chicago.

His father, who answered the door, woke up the 20-year-old and told him the Secret Service was waiting for him.

"I thought he was kidding or I was dreaming," Martinez told Mashable.

Days earlier, Martinez had tweeted what he claims was a joke about killing Donald Trump.

Martinez said the agents "questioned the hell" out him — about his personal, medical and employment history, if he was a U.S. citizen and if he'd ever purchased weapons. They wanted to determine if he was a real threat to Trump's life or if he was just another Twitter user thoughtlessly sending a tweet they'd come to regret.

Martinez's experience mirrors those of other users who spoke to Mashable. If you send a tweet about taking out any presidential candidate, you can expect a visit from the Secret Service.

Brooooo the fuccin police really came to my house ab that tweet 😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳😳 — SC: SoSaucey (@So_SauceyEnt) March 7, 2016

Though a Secret Service spokesperson declined to comment on specific threats against Trump or any other candidate, he cited two laws outlining the duties of the agency and how it handles threats against candidates.

"If you see anything that applies on Twitter, we're going to investigate it."

"If you see anything that applies on Twitter, we're going to investigate it," the spokesperson said.

Under one of those laws, anyone who "knowingly and willfully threatens to kill, kidnap, or inflict bodily harm" upon a candidate can expect a visit, face fines and up to five years in jail.

This practice isn't new to the 2016 election. In 2009, the Secret Service expanded its "Internet Threat Desk" to handle an increase of threats against President Obama. In 2012, the Secret Service asked Twitter users to report suspicious tweets. A campaign adviser for Trump was spotted flagging threatening tweets in October.

While some users may send the tweets as jokes, it's clear the federal government isn't laughing.

One user tweeted a photo in December showing agents outside his window. He claimed he was "raided" after tweeting, "Ima shoot Donald the next time I see him."

Got interrogated and room raided cuz of this tweet smh pic.twitter.com/dDK5L9zNPT — Kevin Out Chea (@WhoIsKevinChea) December 30, 2015

A man in Detroit said agents met with him about his tweet referencing the assassination of Trump, Jeb Bush, George W. Bush and Gov. Rick Snyder. The user said he sent the tweet "jokingly."

A screenshot of the offending tweet that got @KingOfStatusB a visit from the Secret Service in February. Image: Twitter

A 29-year-old Iowan woman said she "tweeted something like 'just let me shoot, you ass'" while waiting outside a gun range as Trump's sons shot rifles inside. Agents showed up at her workplace and told her she could spend 10 years in prison for her now-deleted tweet, of which they had a screenshot.

One of the agents asked if she liked her job — she work at a hospital in Des Moines — and openly wondered what her coworkers thought about her. They also said they visited her elderly grandparents.

When she began crying, a second agent who was dressed in a CrossFit T-shirt, said she "needed to show more respect."

The woman, who tweets using an avatar of a cartoon giraffe, said it was a struggle to offer an explanation to the agents.

"I couldn’t see how anything I said could be interpreted as a threat unless you have very poor reading comprehension," she said.

Government authorities like the Secret Service can legally request user information from Twitter. If they don't have a court order, agents fill out an "Emergency Disclosure Report," detailing the nature of the threat and the person targeted. Of the 2,673 information requests Twitter received from the U.S. in the second half of 2015, 588 were "Emergency Disclosure Reports."

While the company doesn't comment on individual investigations, Twitter spokesperson Nu Wexler pointed out that criminal complaints sometimes list private information such as IP addresses, email addresses, phone numbers and direct messages that authorities obtained from Twitter and other social networks.

The Secret Service isn't just tracking what happens on Twitter, and it doesn't only look for threats against Trump.

An Egyptian student who posted a comment to Facebook about killing Trump was recently arrested at school and has since been told to leave the country within 120 days.

In February, the Secret Service tracked down a Bernie Sanders supporter who tried to place an obituary for Hillary Clinton in a Las Vegas newspaper — a stunt he claims was for "political humor."

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