I know this is an old thread, but I thought I would add my 2 cents worth!
I have loads of married men as friends on FB. I met them in a Bible study, and most are pastors or missionaries, plus a couple of Seminary profs. They post pictures of their wives and families, as I do! I also have married make friends here on CC.
To to be honest, I have never thought about it. My husband and I trust each other totally. We know each other's passwords, and I know he has women friends on his profile, but it isn't an issue to either of us. Or who I add!
Maybe I would feel different if he was my boyfriend and we hadn't been together very little long. But being married means trusting and loving your spouse. It sounds like a terrible, paranoid and legalistic life to be constantly checking up on your spouse on social media.
Besides, the chance of actually meeting any of these men I friend is slim and none! I am absolutely and totally committed to my husband. I guess maybe this is not a temptations that we have in our marriage!