Hello, reporters! This one is journo-made and journo-stamped of approval.
Blacklight is a tool created by The Markup, which is a newish news outlet covering tech from a public service angle. It returns a report on the various trackers, ads, and sometimes funders behind a website.
For instance, you can see that right here on TFR we’re tracking you in three places (sorry), although apparently that’s less than the average of seven (you’re welcome).
I’ve heard about Blacklight before, but only really became familiar with it when ProPublica reporter Craig Silverman gave a talk at MisinfoCon recently. You can see his other recommended tools for investigating ads here, if that’s your kind of thing.
Blacklight seems like it would be good for if you are backgrounding a site (or ad company) or are just fed up with getting tracked and such and want to equip yourself with knowledge out of spite. In any case, happy tracking!