I would like to know why you have let BF3 become a hacker's paradise ?

EA and DICE have partnered with Punkbuster to provide the anti-cheat enforcement for BF3 and many other games.  By its very nature anti-cheat is a measure\countermeasure race and Punkbuster keeps the vast majority of hacker and cheaters off of Punkbuster enabled servers.  If you are encountering a lot of suspect players please ensure that you play only on Punkbuster enabled servers, and if witness any hacking be sure to report the suspected cheater and provide any evidence such as screenshots, videor, and links to battlereports.