How anyone can deny that google is not using a filter is beyond me. All google.com and google.co.uk searches are going through a filter. To look at what the results should look at search from:
I also did a test. I had a website merchantaccountaffiliateprograms.com ranking high for merchant account affiliate programs.
I started an adword campaign and the day later that website was gone from the search results. Of course that website was not gone from google.se since the filter must only apply to spanish websites.
Antoine