We used a tracking code for ads on our site, like this:
We blocked /folder/ in robots.txt and put nofollow on all links on the user side site.
Google indexed all the URls (about 100 ads from various advertisers) and was listing the /folder/track.php URls in the SERPS.
So, instead of the track.php file returning a 301 header once the information had been logged, it returned a page saying "you are being forwarded" with noindex/nofollow/noarchive meta tags on it, plus a 2 second meta refresh to the advertiser's link. We removed the robots.txt block so Google could see the noindex/nofollow tags.
Now, Google is still indexing the URls but with the information from the final landing pages! When did Google start following meta refreshes?! And how do I stop Google from indexing these tracking URls?