though i believe that they are harmless, this is ur warning that they may be offensive to some....and im sure some have seen these b4...
KONTINUE AT UR OWN RISK!!

http://www.youtube.com/watch?v=OZmEVgGMd-Q
http://www.youtube.com/watch?v=ohAuWZJmxTs
http://www.youtube.com/watch?v=U3F6olfXwCU
http://www.youtube.com/watch?v=xp4QVYNAFcQ
http://www.youtube.com/watch?v=yjSGtua_RNU
http://www.youtube.com/watch?v=FHtPcuo9cBI
http://www.youtube.com/watch?v=swKY5tLYLI8
http://www.youtube.com/watch?v=4F7TMlrDXtw