security expert bruce schneier says no; he says much of it is just "security theater." >> bruce schneier: security theater. it's a phrase i coined for security measures that look good, but don't actually do anything. >> stahl: schneier, who's been an adviser to t.s.a., but also its most persistent thorn-in- the-side, says there are too many silly rules. >> you have a little bag with liquids. >> stahl: take the baggies, which became a rule in 2006 when british authorities uncovered a plot to bring liquid bombs on board airliners headed for the u.s. schneier says the liquid limits may make us feel safe, but do little to stop terrorists. >> schneier: if you try to bring a bottle of liquid onto an airplane, a screener's going to a see it, look at it, say, "oh, look, it's a bottle of liquid." toss it over her shoulder into a trash can. >> stahl: they... they don't test it. >> schneier: of course not. no, and they don't even... they're not even scared of it. they put it in a... a trash can right next to them. that's where it stays all day. all right, let's say i want to smuggle a liquid on an