In the previous post, I mentioned how verification companies can help monitor where your ads are appearing. But that is a cure to the problem after the fact; your ad already appeared on inappropriate section of the internet.
There are services available which prevent your ad from appearing at pre-determined section of the internet.
Companies have the technology to monitor the section of the internet where the ad is about to be served and stop it if it is not appropriate. These companies have very extensive algorithm which rates almost all the pages on the internet and then use this rating to make the decision of preventing the ad to be served.
Essentially, they create a firewall in between the publisher and the consumer before the ad is served.
I haven't used these technologies but feel that using them will really make the publishers accountable in terms of content and geographical location. It gives more and more control in markets/agencies hands.