"Facebook's business is data collection in order to sell more effectively targeted advertisements. While massive data collection is not new or unique to Facebook—search engines such as Google and Microsoft's Bing have the same feature—Facebook is unusual in that it actively strives to make that information personally identifiable. Facebook accounts tend to use our legal names, and Facebook relationships tend to reflect our real-life associations, giving the company's data a depth and breadth that Google or Microsoft can only dream about.

Among the pieces of personal information that the site asks users for is religion. As with most pieces of information that Facebook requests, this is of course optional. But it's an option that many people fill in to ensure that our profiles better reflect who we are."

I actually hadn't considered this angle before now. And this is bad. Imagine if someone decided to do bad stuff; hiding a religion on your profile isn't necessarily enough (especially if Facebook tracks changes), but analysis of messages sent to contacts abroad could also help reveal you.

I don't live in the US, so I don't have a lot of insight as to how US laws work in this regard. How difficult would it be for him to do something like this?