Two recent tech stories, one involving Facebook not deleting pictures for three years and the other Path sucking all the contact data of its users on their servers, show once again that posting stuff on the Internet is not as straight forward as most people think.
Just because you hit a delete button does not mean that the content is really deleted from the web, it’s not as simple as on your local hard disk. And just because an application did not ask for all your private data in the first place does not mean it cannot get it at a later stage without your approval.
Posting on the Internet is like getting a tattoo. At the moment, it might seem like a great idea, but as soon as you get sober it will be impossible or at least very hard to remove without any trace.