Thanks to Mark Russinovich for tweeting the photo of an ATM in Kiev. I think it's probably safe to assume most people can tell straight away that MSPAINT on the ATM screen is all kinds of wrong so I'd say that's a good way to warn people to not use the device.
Thanks to @Futuristprophet for tweeting this meme depicting a common misconception about what private browsing can actually do. Private browsing means that no traces of what you did are left behind on your computer - your own computer won't record things in your browsing history or cookies.. It doesn't mean that the NSA can't see and record everything you (and everyone else) does online at the network level.
Thanks to Christopher Soghoian for raising awareness of the fact that the FBI has been using such tricks as impersonating legitimate news organizations' websites in order to plant malware on suspects' computers.
It's a little less configurable than the SQLi Name Tag design I made, but the simplicity of it is more elegant (at least to those who know what they're looking at). Be sure to check out some of the other security-related t-shirt designs by websegura.
I certainly don't suggest anyone actually do what this commentor suggested, but it is true that a seal is usually seen as a sign that the sealed item hasn't been tampered with. Hopefully the seal created by this bag re-sealer is conspicuously different than the one created by the snack manufacturers.