Reporting inappropriate Google ads

To whom should I report an inappropriate Google ad? Thanks.

Without trying to sound funny, I think you need to report it to Google. At least, that’s my memory of the previous threads about this same thing.

Here it is. Sorry, it is hard to find.

http://boards.straightdope.com/sdmb/showpost.php?p=7697105&postcount=5

Thanks, and done.