This is probably as hard as removing a drop of ink from a glass of water - not entirely impossible but quite hard. Furthermore you have do find a mechanism that

This is probably as hard as removing a drop of ink from a glass of water - not entirely impossible but quite hard. Furthermore you have do find a mechanism that enables you to prove that the information you want to delete refers to you and that it therefore is you right to do so. Failing on this may easily turn the thing into means of censorship. On the other hand it is probably sufficient to remove the easily discoverable instances of that information because not many people will try really hard to come up with something. And the ones that do will probably also do so outside of the internet.