If you look at a member's page you will see two items listed.
Watching (member name) and a number
(member name) Watched and a number
No you are not being stalked. This simply shows your interaction with that member.
Watching you simply means that member has read your content, profile, mail, votes for 31 times.
Watched means that you have done the same with them.
Nothing sinister or creepy about it at all. It's just a tool to keep track of the activity between you and that member.