Using copyleft software for privacy and freedom
One very easy way to preserve your privacy online is to stick to using free and open source (copyleft licensed) software. This is software that is free (as in freedom) and released with it's source code publicly available, so you can be confident there is nothing hidden in the program that will spy on you or take control of your computer away from you. If you are using proprietary software (e.g. Mac or Windows), you should have less of a privacy expectation than if you were using GNU/Linux or a similar free operating system.