There are many adsense sites on the web ,anybody know how did google punish an adsense sites ,when they find these site ?Which one will be punished ,the website or the adsense account ?
It depends on the reasons for the "punishment". If the publisher violates the TOS with fraudulent clicks, then his account is banned, but I've never heard of site being banned as well. People mistake Google the Search Engine and Google Adsense for the same entity. They may belong to the same company, but they are in charge of two completely different areas.
There are 100s of MFA sites reside on Google search results. They exist for months, and they don't touch them - I suppose, they close their eyes on the TOS point -"sites made for the sole purpose of displaying adsense ads". These guys invest huge sums in AdWords, bring huge money to Google via AdSense. So, I strongly beleive, if the site breaks the only this point, it's safe.