Question: I consider Facebook to have information that is personal and that I only share with close friends and family. However, in my new workplace I’ve been asked several times for my Facebook username and/or have been *friend requested* and I don’t want to sound rude by telling them that I don't want to add them as friends. 

Any suggestions on the way I should handle this?

Answer: 
I have a simple rule for Facebook:

* We must have shared a meal together.

If you like this coworker enough to go out to eat with them, you can add them (possibly in a Restricted list as [Jake covers](https://workplace.stackexchange.com/a/25829/7194), if it was more of a one-time whole-department thing.) If you don't, you're not really friends.

The odd thing about this is that the rule spares everyone's feelings. If you say "I've been thinking about our relationship and I don't think we're friends, just coworkers" they will feel bad. If you say "I created an arbitrary rule before I ever met you and at the moment you don't qualify according to this rule" they don't. Sometimes they even say "That makes sense" or "I like that rule, I might start using it." No-one has ever told me I should change my rule. Oddly, no-one has ever campaigned for us to share a meal in order to qualify to be a FB friend. Brains are funny things.

What really counts is that the rule exists, not what it is. It could be "I have to have known you 6 months" or "we have to have met before I was 12 years old" or "at least two of my current friends have to have already added you" or "we have to be so close that I know your children's names" "we need to have attended at least one wedding together" - really anything that sounds reasonable and impartial. It makes it easier for you to evaluate these requests **and** easier for others to accept being rejected for not meeting the impartial rule.
My approach is to have largely disjunct sets of social networks. You're a work colleague? Fine, I'll add you on LinkedIn and Google+. You're someone I met socially and you want to link up on Friendster? Fine.

It does go both ways, I know a lot of people who socialise in a work-like way. They have a small business, they're Amway victims or whatever. If I don't see them as related to **my** work I will keep them on the social side. Or the black-list, if that's how I feel about them.

I have cross-over stuff, like selling photos and hanging out with photographers, so I run multiple streams/sites for my photography. I generally add those people on both career and social sites, but I also partition them within the site. I have facebook groups for "family", "friends" and "clients", for example.

So my answer to those requests would be "why don't we use LinkedIn" (or whatever).