Two words - SECURITY DEPOSIT.
I think if it were a family, you're running a lower risk, but it increases the risk that the whole village would end up in the house.
I would rent to one, but only if he stipulated in the lease that only he would be living there. (Maybe creating a provision for a girlfriend or something.) Get 3 months rent up front considering eviction procedings can take a while. Other than that, what's the guy's demeanor, his cleanliness? If he's a nice guy and he'll pay, then rent to him!
ETHICALLY, as a REAL US citizen is where I find a problem. You're an enabler, but the argument can and would be made that if you didn't rent to him, someone else would. Atleast you have some control over him though, maybe you could add in that he does all landscaping! [;)]