Tim, an attorney had worked for Bush Administration. Though the exact reason behind Tim joining Facebook has not disclosed, it is probable that Facebook would utilize his experience for protecting personal information, given by its users.
Tim Muris joining Facebook has already created a controversy. The Electronic privacy Information Center has filed a suit against FTC. Facebook is blamed for their involvement in unfair commercial dealings by which they have violated protection issues of the users.
Whether Tim Muris has joined Facebook is still a mystery because neither Tim Muris nor Facebook has revealed the truth yet.
source : http://blog.taragana.com/index.php/archive/do-not-call-register-founder-tim-muris-joined-facebook/