In Facebook's new privacy settings, regional networks were dismantled completely. However, in its place, the "friends of friends" setting has become immensely popular. This is a very dangerous proposition and I urge you to restrict your privacy to friends only. There are far too many people that can see your profile and it may even affect your ability to get a job.
How many "friends of friends" will have access?
Friends of friends is much more dangerous than the regional network. Let's take the highly conservative count of 200 friends. Let's say each of them has, on average, 200 friends. Multiply that and a potential 40,000 non-friends could have access to your profile and photos. This is highly conservative, because in my friend count list, 12 of the top 20 have more than 1,000 friends each, and many other have anywhere from 400-900 friends. Heck, one of my friends has 1,950 friends.
Places, location, and event "friends"
Before the advent of Facebook Pages, a friend profile was a common way to get the word out about your product or location. I've gotten friendship requests from the "Port of Long Beach" or "PRSSA Long Beach." This can be dangerous, because they can be the mutual friend link that would otherwise not exist. For example, CSULB ASI has 1,200 friends. If I became friends with CSULB ASI, I potentially have access to more than 1,200 people's photo albums, notes, etc. if they chose to set friends-of-friends privacy.
Pages do not have this problem. They're much better because you don't have to disclose as much private information as a friend link would (and it's a pain to set limited profile). This is probably why they've become far more popular than these friend profiles. I don't recommend severing ties with these profiles, just set everything to friends-only to avoid this problem.
If you're networking well, there's a really good chance that a potential employer can see your profile if you have friends-of-friends access. For example, I'm friends with the adviser at the Daily 49er and the CSULB photojournalism teacher. Both used to work at the Orange County Register and the photo teacher used to work at the Associated Press. When I sent the name of the Associated Press internship coordinator to the photo teacher for a recommendation letter, she came back to me and said, "Hey, i used to work with that coordinator." So if that coordinator had a Facebook and I had friends-of-friends privacy, she could potentially see my photos, notes, etc. which is a really bad thing.
And what could she see? Well, by default (and Facebook is really stupid), the profile photos album is accessible to friends of friends. As I stated in my prior post, if you have less-than-work-safe poses (such as holding beer containers uploaded before your 21st birthday), this could look bad. Photo album access can also be compromising, especially those of parties. I also believe that notes access is Everyone by default. Now that it shows up in profile search, employers could see potentially embarrassing "25 random things about me" notes or other things.
The point is that you shouldn't take the risk. Any potential employer's evaluation of you should purely be based on what you submit – the resume, cover letter, and the interview process. They should not have the access to make assumptions about your social life, relationship status, or other things not pertaining to the job description. Legally, they can't ask such questions. But I don't believe there's anything illegal if they happen to find that information on their own if your friends-of-friends privacy setting grants them that access.