I’ve included it in a few lists before, but I’ve never specifically discussed Disconnect. TL;DR it’s a wonderful extension for all the major browsers that lets you control and block some of the nefarious tracking that sites attempt to hoist onto you.
Started by a former DoubleClick engineer, Disconnect whitelists (or blacklists) sites you don’t want tracking you, either explicitely with cookies or analytics tools, or indirectly through social sharing buttons and advertising. The plugin installs a toolbar button which allows you to view the sources of blocked material at a glance.
Aside from remote tracking, Disconnect also provides a WiFi protection service which claims to route your traffic to prevent snooping. I haven’t had a chance to look into this further; specifically whether it prevents Firesheep style attacks on poorly designed sites some of us still have to log into. Additionally, I’d assume Disconnect would then be able to track you instead, much like any VPN provider. Still, if you trust Disconnect more than your free hotspot, it would make sense.
Perhaps its best feature is set and forget. I use NoScript on SeaMonkey and Firefox, so many of the tracking scripts Disconnect blocks are simply never loaded. If those extensions are too much work for you to maintain and use though, Disconnect may be the next best thing to protect yourself, and without any extra work on your part.
I’ve installed it on all my family’s computers, and have an urge to break into your house and install it on all yours as well. I suppose that introduces further privacy and security concerns though.