Where would Facebook etc pick up the info they use to display ads?

[canucktico]

Recently what is displayed at the right of my Facebook page etc switched to Spanish/Costa Rica??
I do have family there but my native tongue is English so I was wondering how it decides what to display. youtube also is showing Spanish subtitles.
I work on the internet so I can't have my research in Spanish or affected by none North American content. Any help would be greatly appreciated

[Sarcasticdesk476]

It's got all sorts of things to check out what you're doing on the web from cookies and your profile.

You can turn many of these features off, it just requires patience as you wade through the many settings.

This guide shows you how: http://www.hildenoaks.co.uk/suggested-fa...ttings.php