Found out there are some cookies that have spyware to track your every move. Using Macscan, I found a number of cookies that were doing this.
First check your web browsers and make sure, your preferences are set to keep cookie settings from websites you visit only; not advertisers sites.
Here is a webpage describing Macscan. You can get a demo.
There is also a a demo version from intego, which is more expensive.
I make no claim on which program is better.
Also, a site called Secunia for finding vulnerabilities on your Mac.
Last but not least, is a talk with Victor and Paul about security on the Mac. They discuss, five ways to improve security. Jon L