You can use NoScript, a Firefox web extension, to counter tracking, although you'll have to look up which sites are kosher each time you want to unblock Java or another script they run, which will be both time-consuming and not entirely certain. There's a website
that lists all of the top sites currently using canvas fingerprinting, so you could check sites against that, but it may not be updated frequently enough to catch new offenders.
You can also download Chameleon
, a browser designed to avoid this kind of tracking, but it's still a low-key experiment, and not very user-friendly unless you're comfortable setting stuff up from Github. [I don't know if it works on Linux flavors, most browsers run great on wine, but it's kinda' the long way around the barn..- JR]
If you've accepted your fate as The Tracked but don't want the data used for ad targeting and profile building, you can manually sign up for opt-outs from the businesses doing the tracking. AddThis would be the big one, since it does most of the known fingerprinting.