Do you use Avast antivirus programs? It has come to light that they harvested user data and sold the information collected to a firm called Jumpshot who in turn sold to other companies: Google, Microsoft, Intuit, to name a few. This pertains to both PCs and Macs. This includes both free and premium services. So while you are trying to protect your privacy and data, Avast is going behind your back and selling your data and privacy.
To be fair, you have the option to opt-in to allow some user data to be collected, but you are not really told how or what is being used. The data collected includes location lookups, searches, YouTube video listings, Google Maps, LinkedIn, and various others.
Think twice before you download a free or even paid software. Don’t allow them to collect information.