i was using them. somene in this forum said that to me and i removed thier code but on one blog i removed their code 1 days later,and 1 days was sufficient for be banned with google i lost all visitors for this blog with google, google now shows this blog with this text: This site may harm your computer.
Thanks for informing all of us..i also had some prob with pay ads...my site redirected to some ugly sites when i used it so i removed it the very next day