I wouldn't either. I don't have social media accounts set to public to protect myself as it is. If you're dumb enough to leave them open publicly, you subject yourself to too much scrutiny. I don't post ridiculous things anyway, but it's my business. I don't need an HR person rooting around in my accounts, etc, let alone the government. I'm actually annoyed that our company wants you to have a LinkedIn profile and HR do check it. To me, it's just Facebook for adults and there is nothing in my contract that states I am required to use social media on behalf of the company.
I don't know about the rest of you, but we have to do yearly training on data classification and storage so we don't violate laws internationally by collecting information and mishandling it. Hubs and I work for the same company and when we got married, we only told HR, as it was a requirement for personnel profile updates, benefits and beneficiary information. We kept our work relationship professional and our personal lives at home. When my boss found out a year after we were married, she was like "why didn't you tell anybody?" and I just said it was none of anyone else's business. She knew at that moment that based on our data security policies, she couldn't say anything more than that. She could have been fired if she shared personal information that wasn't hers to share.
The US, in general, is far too lackadaisical with people's personal information.