Puzzling question?

[TenGrandDame]

I know that no matter what you do on the internet these days you are being watched by big brother or google etc. BUT when it comes to someone spying on you from their own private at home computer, laptop or tablet or iphone etc than this a worry and concern especially when the person follows you around from website to website and in the process sabotages your good name where ever it is possible to do so or tries to ruin everything you do for no other reason other than jealousy. I can't elobrate more on this right now for obvious reasons but I know damn well it's happening to me. This person is obviously not using spyware that a antivirus can pick up and block or delete off your computer. It is not possible that this person is collecting information about me just through using search engines as I change my usernames etc all to frequently. So I am left wondering how this person is able to watch every thing I do on the internet (spy on me)? I have found this website that explains what the person "COULD" be using!
http://www.cnbc.com/id/100583418
Does anyone in here that is tech minded with this sort of thing have any knowledge on how myself and others in my position might be able to put a stop to others using software like the above to illegally spy on us please?
I cannot figure out any other way the person might be spying on me like they are without using a search engine/s other than with software that a antivirus cannot pick up on block or delete off your computer. Be interesting to read some of the feedback on this should I get any. Thanks everyone. :-):help: