I'm not aware of a list.
Sometimes you get lists when there's a procurement process. Often you get a number of companies that register to sign up for that, but that takes a little bit of investigative work from journalists to really uncover that and it's never complete.
I will say really briefly that some states—and Ms. Bhandari may or may not know more about this—do actually require data brokers to register. That might be something to look at in connection to these types of companies if we want to get more transparency on exactly what is happening on the ground.