Google has been quietly doing that for a while now as well. In fact, they even do it in gmail... spooky....
If I click on one of those Viagra links- big brother's looking...
That wouldn't be google's problem, it would web position's problem, although we don't have that problem with webposition either...
Now, if they could copy google's "gclid" parameter on paid search so I don't have this problem....
Log Analysis with Yahoo...
I'd be a hell of alot happier