Geocities and Google AdSense

This is my latest discovery. You cannot take the names of 'Geocities' & 'Google AdSense' in the same breath.
As most of you might be aware (I hope I am right)of my personal web page, is hosted on geocities. I, then registered with Google AdSense (thought of making some easy bucks :)). The ads started appearing on my web pages, without any problems.
However, after some days when i check my site, I find that all the ads have been removed by Yahoo & there is no way that they intimate the owner of the site.
I think Yahoo should behave more professionally and should inform the designer upfront before taking such heinous actions.