Erik Bornmann 

Actually, as stated in my edit summary, it was a RFPP request to unblock.  I am actually surprised that you'd think that (not in a bad way).  Futhermore, it seems that the editor only used two sock puppets which probably stopped.  Long-term semi-protection is never the answer, articles are normally only protected for a few days.  If an article was semi-protected for weeks because of only one user, that would sort-of defeat the whole idea of a wiki.  If the user comes back, you may either ask for him to be blocked (specifying he is a sock) or ask for re-protection.