You could also try a configurable firewall like Zonealarm. I've used it for years and swear by it. In addition to blocking unwanted access, it will show you each and every program on your computer that is trying to get to the net. You can also configure it to filter sensitive strings like your SSN, credit card numbers, etc. It helped me catch the US Army putting my SSN in the query string of a URL on their portal (meaning the SSN of me along with every soldier using their site was sent in the clear). I also caught IE rifling through my favorites and sending them to an obscure IP address that I traced to MS ownership. What other secret shizzit are they doing?
Reality is merely an illusion, albeit a very persistent one. - Albert Einstein
What isn't realized all that often is the 60-hertz constant barrage of electromagnetic pollution that is given-off by the electrical grid: inside and outside of your home.
You would be surprised at the amount of low-level radiation or electromagnetic pollution that we're bombarded with on a daily basis: Radio signals, power generation/transmission, cellular, microwave signals, etc. The only way to escape it is a Faraday Cage, which isn't practical.
I spent a year and a half of research on this topic for my Bachelors Thesis. I found over 100 published experiments, epidemiological data, and other studies. My own experiment was inconclusive, which studied the effects on Behavior, but the citations I found have years of data.
So what to do? Even if you move to the recesses of the world, there are still wavelengths from distance towers, the sun, etc. Some people claim "Sick Office Syndrome" from excessive exposure to business machines and computers (monitors especially), but that is also inconsistent.
My conclusion: requires more study. It's hard to say if it increases susceptibility to cancerous tumors or similar. The strongest correlation is between the proximity microwave towers and illness. High-voltage power lines show an increased propensity, but it's also spotty. What can you do, I guess...