Hay, everyone tells me no dont put that on your site google will ban you. And i was thinking, how google acctually monitore all the actions, site content, Ip adresses, everything? i mean they got 100000000...... adsense acounts. and triple that and you will get the number of sites which have adsense.
A few months ago i put google ads on a PTC website, which is against there TOS which i never knew about. I earn on avg $1-3 per day and they still were able to email me and say your breaking the terms and they disabled the ads on my PTC site. So whatever they use, its a great tool! Regards Kev