An project I was working on was required to always identify users who took part in certain transactions (think of financial processing regulations).

Because some of the contacts on your phone might only contain a mobile phone number (and no name) a mandatory 'recipient' field was thus created to be filled for each transaction. This name was then checked against some international UN sanctions blacklists (you know, so Bin Ladens cousin can't use the thing...).

Only thing was... you could simply enter whatever name you wanted to. Like '%#^@/}(#' or 'John Doe', or 'Micky Mouse'... Everyone was well aware of this - but because ITS' THEM RULES we had to do it anyway.

Hope Bin Ladens cousin doesn't figure it out. :P