I'm in the same boat with you. Been in the industry for 20+ years and I do not have any social media. One of my employers constantly pushes for LinkedIn involvement/activity but I simply refuse to participate. I did not become an engineer to share blog posts or comment on things in front of hundreds or thousands of folks.

However, I do have a few different websites that I used to be very active in but have since (for the past 5 years) rarely use them. It's usually only to share something interesting and to keep my web-deb skills somewhat sharpened.