Random observations made while I was reading through the submissions:
It was a surprise to many people that battery level was available to trackers; it surprised me too when I first learned it.
People had lots of cookies (hopefully now mostly removed), and there was general surprise at the amount of tracking that goes on. Blocking 3rd party cookies is probably a good compromise for most people (and some browsers do that by default).
I think there was some misunderstanding of what private mode does in a browser. It only promises to remove things like cookies after a session, but any information that you provided goes to the sites you visited directly or indirectly.
People had widely varying experiences with the temporary mail systems (which echoes my own experiences); each one had people who liked it.
There are at least 2 people who don't have FB accounts!
Most people implied that they made some changes and will be more cautious about browsing in the future.
Thanks for the comments and suggestions for improvements. I agree that the lab was too long; I will find a way to trim it for next year. I will also clarify some of the background and requirements that were not clear.
I found a site that is much worse for tracking than anyone else found: epicurious.com, a cooking site. This may not be a world record, but it must be a contender.