It has been raised many times here, PW or any other website with google-ads has no control over the content of ads. It is based on IP and cookies, search is not the only reason.
Like I've uae IP so I mostly see uae based ads and ads are mostly of the content I've been viewing over past some period.
Right now I'm having ad of some plus500.ae, some forex related stuff 
Please click AdChoices tab on your screen, it is giving definition: demographic and interest-based advertising 