Data, once put on the internet, are quite hard to delete. You can most likely delete (or ask for deleting) them from place where it has been originally distributed, but you can be never sure where else it has appeared.
Recently, I've seen several requests to remove some data from Gammu testsuite. This testsuite was created using public data available in our bug tracker, simply to be able to verify that we won't break stuff which was earlier fixed.
It turns out that some people did make public some very private stuff, which was included in the testsuite in the end. None of the developers had clue about content of these messages, being in language which nobody of us understands (and being too lazy to run them through Google translator to understand them).
Of course we've removed the data on request, but it's probably already copied in dozen other places on the internet...