It's a bad play in a vacuum but it does increase the action. A straddle is not as dumb as a raise in-the-dark before the flop, which can be any amount and does not give the bettor any opportunity to raise his bet.

Straddle = 2x the big blind on UTG. Double straddle = 4x the big blind on UTG+1, after UTG has straddled. On my idiot table it has gone as far as a quintuple (2^5 or 32xBB) straddle. To be funny I guess.