I'm actually doing it right now.

I have a friend who was "renting" a room from a friend for about two years. He rarely paid the guy and then got fired from his entry level job for being a shit then went for months of being unemployed without paying his landlord anything. In attempting to repair his vehicle himself he screwed it up so badly that it had to be junked so then he had to borrow his landlord's mom's car to use when he finally did get a job. In addition to being a lazy mooch he was also a tremendously condescending asshole to everyone, including his landlord. I was friends with the landlord and advised him to kick the guy out, thinking the idea would shock him into straightening up.

Well, lo and behold, my "can't say no" attitude, lands me in a situation where said guy is now living with me in my tiny place wherein I pay all the bills. It was supposed to be for a little while until he got himself together but it's been five months and he's always broke even though he works nearly everyday and eats out constantly. We share my car and while he does contribute to gas and occasionally buys me dinner or a pack of smokes, he's broke, doesn't buy groceries, doesn't contribute to the bills, and has no plans of moving out.

He's also incredibly negative and shitty as a person. I'd love to ask him to leave but I've had an emotionally devastating year and he's seen me on some of my dark days and knows some of my personal weaknesses that only someone who lives with you knows. I know that as soon as I say anything he'll run his fucking mouth to everyone within 100 miles and ruin my reputation and make me out to be a monster. In addition, I can't bear the idea of throwing the dude in the street since, even though it might be what he needs to shape up, I can't let myself make someone homeless.