I hope the article's authors aren't taking the position that mass surveillance is a bad thing, signifying a breakdown in civilized norms ... after all, they're using the same methods to "track the trackers."

Surely there is a difference berween "surveiling" records of institutional actors that answer to the public and dragnet tracking of individuals operating in their private capacity.

In the US it's not uncommon to get on the wrong side of a police officer for some personal beef, and the police officer begins to harass you using legal tools provided to them.

It's also not uncommon for police officers to use their tools to stalk women.

Now we're given the same untrustworthy officers full profiles of an individuals travel history without a "need to know". If you can't see how that's dangerous, I don't know what to tell you. In the US if someone is threatening your life, you can typically shoot them if you're out of options. You usually can't do that with an officer, even if they're off duty. The rest of the cops will stand behind that thin blue line and harass you.

Maybe it's one of those situations where it takes a good guy using surveillance to take down a bad guy using surveillance?

It's 1938.

When nazis kill jews that is bad.

When jews kill nazis that is good (arguably (it used to be obvious but now it is only arguable)).

Symmetric situations are not equivalent.

The "trackers" (in the sense used by the parent post, i.e., those who govern us) are there as our representatives; it is our right to observe what they do in that role.

Judging by the downvotes, there are a lot of surveillance state apologists/quislings in here! Oops, I mean "founders".