I am convinced that people have a responsibility to guard their reputations online. Here are some techniques to protect your identity from unethical online marketers and to prevent possible embarrassment from unwise comments and searches.
1) Use a search engine that doesn't track your searches.
If you are logged into Google for any reason (YouTube, Gmail, or Google Reader) and perform a Google search, Google saves a record of your search. You can disable (pause) this search history and erase your history of previous searches.
2) Clean up viewing history on YouTube.
Your viewing history of YouTube is available here. You can remove any videos from this list.
3) Keep your operating system and an antivirus program up-to-date and scan your computer regularly.
One of my previous jobs involved troubleshooting customer computers. For PCs running Windows, I would run the program CCleaner (there is a free version) to remove unnecessary temporary files from the computer. This shortens the amount of time required to run a complete virus scan. The antivirus program I have been most pleased with is Malwarebytes (free version available for home use).
4) If you use a public computer such as one found in a library, remember to log out of websites that require you to enter a username and password. Otherwise, the next person on the computer may access your information.
For example, a friend of mine forgot to log out of Facebook and someone posted an obscene comment to his wall.
5) Avoid pornography and gambling websites. Just don't go there.
6) Monitor your name in search engines. Don't be surprised if someone with the same name exists and has a criminal record. If your identity is stolen, you may find evidence for who is responsible.
7) Avoid posting inflammatory comments on Facebook, Twitter, blogs and discussion forums. If you have left behind embarrassing comments, go back and delete them if possible.