Starting September, I noticed in the section Unauthorized Sites that our code is showing up in a pay to click site. It's a UK site (we're US) that pays its members to click on the ads. I can't see where our code may be as it is a members only site.
Traffic from this pay to click site has grown to the point that it is now the #2 biggest referral traffic for our site.
It's worrisome that our code is showing up in a PTC site, which we have nothing to do with. We don't do pay per click, and the only times we do Adwords is when we get the $100 certificate. Other than that, we don't do paid advertising of any kind.
Of course, we will never authorize that site in our Adsense panel. But what else can you do when your Adsense code ends up in a bad neighborhood like this, which you have nothing to do with?