Transportation contractor Cubic Corp. and GE Security have teamed up to develop a security system that they say could help prevent terrorist bomb attacks in subways. The system relies on a button included on a ticket vending machine, which scans the purchaser's fingers for traces of explosives. The scanner could also be integrated into turnstiles, so that transit cards would be scanned for explosive substances as they're swiped. While it sounds somewhat plausible, we're a little wary about the program's chances for success. Cubic, it turns out, is the company that built New York's MetroCard system, and if this is as reliable as that -- anyone who has had to endure an endless cycle of  "Swipe Again Here" prompts knows what we mean -- we don't stand a chance.