Some good advice from the Wired Wiki.
Nowadays when we’re on the road, you have very little to worry about when it comes to getting the information you need, corresponding with e-mail or instant messaging or writing up those important spreadsheets. As a nice bonus, if you’re just bored and need to entertain yourself on a ten hour flight somehow, you can just sit back and watch some YouTube videos, since a lot of airlines are now providing cheap in-flight wireless internet. But here’s the thing; wherever you have a new way of transferring information, snoops also have a new way of stealing information and sending bad information. So it stands to reason that this new trend of providing free wireless internet in airports and in flight is also suffering a bit of turbulence in the form of malicious hackers.