We also have to pay attention to cell phones -- phones that will activate explosives and phones that take pics. Technology helps us and it also helps the bad guys. E.g., Is that swarthy type innocently talking to a friend on his cell, is he about to explode a remote bomb or is he casing a building and taking pictures of the area? It only gets more complicated these days.
One thing I've noticed so far, is that these *supicious* dudes and dudettes can't help but act suspicious. Almost as if they're fish out of water. Hopefully, this makes them more recognizeable.
I've mentioned before that last summer I witnessed 2 guys filming a building in Chicago. Like a kid with their hand caught in a cookie jar, when I walked within their view....the one guy quickly put the camera down to his side. Later, when I looked back...they were filming again.
There are many islamics working at my airlines...they have internet access [we can access news, etc but nothing obscene of course..and even send email..] BUT why do I see them...and only them... pecking away at their cell phones sending text messages and email from them instead??? Could it be because our emails are monitored????