do you guys have an idea on how to deal with lines like these in the system.log of Mountain Lion?
Feb 13 11:43:11 Manzana.local screensharingd[5664]: Authentication: FAILED :: User Name: fail2bantest :: Viewer Address: 192.168.91.123 :: Type: DH
Feb 13 11:43:43 --- last message repeated 20 times ---

When the person tries repeatedly to log in, OSX just modified the next line (X times) so the above regex does not match anymore.