The Network Advertising Initiative has a great tool to opt-out of cookies and whatnot on your computer that track your behaviour to sell you stuff. It’s really easy to opt-out and worth it if you find it creepy or just annoying that these large companies track what you do online.

The NAI Opt-out Tool was developed in conjunction with our members for the express purpose of allowing consumers to “opt out” of the behavioral advertising delivered by our member companies.

Link to Opt of behavioural advertising.