"Security Theatre" is a favorite phrase of mine. It was coined by Bruce Schneier, a well-known cryptographer and computer security expert, and it perfectly captures the concept of actions that appear to create security and safety, but are really just show. Reassurance for people who want to feel protected but find real security too expensive, intrusive, or just scary.
Signs banning guns from malls, entertainment venues, etc. are one kind of security theatre that comes up a lot on this forum. They're reassuring to people who don't think about the issues, but they do absolutely nothing to increase the safety of patrons. Like much security theatre they arguably make the place less safe.
I've been complaining about various sorts of security theatre to my wife for years, but I don't think she really got it until a couple of weeks ago at EPCOT in Disney World Orlando. After we got our tickets we had to pass through a "security" checkpoint, where a friendly, elderly rent-a-cop quite thoroughly scrutinized the contents of my backpack. He assured himself that the snacks, bottled water, camera, sunscreen, etc. in my pack weren't dangerous and then let us through. Of course, he did nothing about the 9mm handgun and 33 rounds of 147 gr +P+ jacketed hollowpoint ammunition concealed on my body (no comments from .45 afficionados about how the 9mm isn't really a dangerous weapon, please
As we were walking away from the checkpoint, my wife said, in an annoyed tone, "That does absolutely nothing! A complete waste of time. Anybody could bring a gun in here! You did." I just said "Yep, security theatre at its finest."
A very similar sort of security theatre was described in another thread here: concert venues that perform half-baked pat down searches for weapons, pretending (wishing?) that the search might keep weapons out of the venue.
So, what other kinds of security theatre have you guys run into? I'm especially interested in examples like the concert venue where the security effort is just "real" enough that it might dissuade you from taking the tools to protect yourself, but clearly insufficient to keep weapons out.
Oh, and to head off one common one at the pass: Let's not bother talking about airport security. It's the standard example, but I'm interested in spotting some less obvious kinds of security/safety theatre.