PSA - Every time you post a photo of your credit card god kills a kitten.
I know its exciting when you get that new debit / credit card. It has that cute photo of your dog, or maybe your kid or even your favorite sports team. And I know it’s hard to contain your excitement to just your friends and family that are within arms length and all you want to do is show the world. So you post a pic of it on twitter or facebook or name any other social networking service. Now someone has your card number, full name, photo and probably knows a lot about your habits (thanks to you posting it on twitter).
There is even a dedicated twitter account for retweeting such photos. Check it out https://twitter.com/NeedADebitCard and before you start pointing fingres at the NeedADebitCard twitter account remember they are just retweeting what people have already posted publicly.
Though this also applies to concert tickets or anything else with a barcode / serial number. You should never post that stuff online. It’s less of an issue after the event is over but if its a season ticket holder account number someone could use that to hijack your account.