Are you a social media holdout? What are your reasons?

In this day in age it is hard to find that rare specimen among us that doesn’t have a profile on some large social media site. If you are one of them, please list the reasons you have chosen to resist the peer pressure I’m sure you must be facing.

Please only answer if you do NOT have a profile on ANY of these sites:
– facebook
– twitter
– linkedin
(specialized sites like fluther don’t count)

Also, it would be helpful if you could provide your age (or at least a range like teens, 20’s, 30’s)