You may think twice the next time someone asks to borrow your phone.

Check out this video (note the NSFW language) of a prank in which a man in Los Angeles asks to use strangers' cell phones -- only to try to make drug deals.

The reactions are as priceless as they are varied. Some people want to get in on what he's selling, only to be disappointed when he fools them into thinking he's the police. The clip gets better as it goes on, building up to an argument at the 2:41 mark, a physical confrontation at 3:27 and a potential new (and wacky customer) at 3:37.

And, really, if someone asks for your phone, you should be suspicious right off the bat. Everyone has cell phones these days -- homeless people, mutes, octogenarians who still use VCRs. They're as commonplace as the air we breathe, although this video proves that the only ones more dangerous than someone asking to borrow a phone may be someone who lets you borrow his phone.