I hate to post this, but will since it's public info...
I sometimes read 2600 Hacker Mag. You can find it at most Barnes and Nobles and similar places. They publish quarterly. Anyways, there was either a letter or article in the mag several issues back where someone explained how they stole gas for almost a full year. They did it by swiping at the pump and then hitting cancel. Somehow the pump still authorized the gas even though the transaction canceled. I think that article raised a lot of awareness about the issue and most pumps with that problem are now fixed, but I doubt every single one everywhere is. Also, I've read that you should always pay via "credit" not "debit" when you do pay inside since some of the major identity hacks a year or two ago were done by hackers actually hacking the machine in the stores and either wirelessly or via some other means, were able to yank the cc data out of the computers, along with names of the cc owners, etc. Some articles I've read indicate that if you pay via credit instead of debit, your chances of that are less since the computer isn't storing your pin in addition to the cc number, just the cc number...also have read that by paying via credit, you are more insured, but I think that only applies if it's really a cc card and not a visa debit, etc. since debit is really from a bank, not a cc company.