It’s an old Daily Show joke. This Google search may explain:
Or this clip…
Or in interviews…
SIN: One of the rumors that we have that sort of trickles around here is that…
Jon: I once killed a hobo! With my bare hands! You are correct sir!
SIN: Something like that… Basically, the rumor is that you hate us. You hate William & Mary, and you didn’t like your time here, and you would never consider saying anything good about the school.
Jon: Oh no no no, that’s not the case. I didn’t necessarily have the greatest time there. But that wasn’t necessarily their fault.
Or in guest interviews:
In contrast, Stewart repeatedly challenges Christopher Horner, a global warming skeptic from the American Enterprise Institute. At the beginning of the interview, the host compares Horner’s book (The Politically Incorrect Guide to Global Warming and Environmentalism) to the IPCC report: “Yours is more interesting. The graphs and all of the other things in the other one—the data—I didn’t care for it.” Toward the end of the unusually contentious interview, Stewart asks his guest, “Have you ever killed a hobo?”