Making sure that Gullickson was not a threat required more than just an analysis of his online comments—it called for offline contact, an in-person visit, an assessment of who he was and what he was like face-to-face, not just on the Internet. Context is crucial for evaluating the seriousness of threats—both digital and analog—but online threats offer a slightly different set of contextual clues than their offline counterparts. And while much of the hate-filled commentary on the Internet is routinely written off as hyperbole and ranting, threats directed at the president are not so easily dismissed. So, every day, the Secret Service Internet Threat Desk is faced with the unenviable task of taking seriously some of the most extreme online rhetoric and trying to identify potential assassins or terrorists in the deluge of venomous messages directed at the president and his family.

Though most of the public cases involving the Internet threat desk have to do with threats made via Twitter or Facebook, the desk actually predates both platforms. Founded in 2000, the desk was reportedly expanded in 2009 around the same time that threats against President Obama spiked in the early months of his first term. Ronald Kessler, author of In the President’s Secret Service, said that when he visited the Internet threat desk several years ago it was “just a small room with a few people,” but added, “I’m sure it’s much bigger now.” Secret Service spokesman Robert Hoback declined to comment.

Since the Internet threat desk’s founding, Kessler said, more of the threats the Secret Service assesses have originated online, but the overall number of threats directed at the first family that require investigation has stayed relatively steady at about 10 per day—except for the period when Obama was first elected, when the Secret Service had to follow up on roughly 50 threats per day. “That includes threats on Twitter,” Kessler said. “It makes no difference to [the Secret Service] how a threat is communicated,” he added. “They can’t take that chance of assuming that because it’s on Twitter it’s less serious.”

The Secret Service categorizes all threats, online and offline alike, into one of three categories, according to Kessler. Class 3 threats are considered the most serious, and require agents to interview the individual who issued the threat and any acquaintances to determine whether that person really has the capability to carry out the threat. Class 2 threats are considered to be serious but issued by people incapable of actually follow up on their intentions, either because they are in jail or located at a great distance from the president. And Class 1 threats are those that may seem serious at first, but are determined not to be.

Classifying threats into these categories is partly a matter of wording and specificity—whether the speaker has developed a detailed plan, whether they state that they will kill the president or just that someone should kill the president—but also depends largely on the background of the people who issue them. “The Secret Service looks at whether this person has expressed similar plans previously, whether this person has a criminal record, or is mentally ill,” Kessler said. Presumably, that’s why an agent showed up at Gullickson’s house—to assess the person who issued the Twitter threat, not just the threat itself.