I didn't know that's what the digital speed signs are for... I thought they were just a friendly reminder to be at the right speed. I see cameras at almost every intersection these days, anyhow. Nothing new about traffic surveillance and license plate reading.
If we're going to be paranoid about this kind of thing, the only thing to do is quit driving and sell our vehicles. Otherwise, just accept that we live in a surveillance society and there's no way we can change that unless we want to join a class action lawsuit or something like that, and there's not much chance that will reverse the trend. Plus there would have to be a separate lawsuit in every state - a huge undertaking.
So, it is something I don't pay much attention to because I refuse to live in a constant state of paranoia over everything that's wrong with this civilization. That would be a lot to worry about! Instead I just do my best to drive at the speed limit posted, and trust the rest to God. If something is to be done to fix things, it probably won't be done by me, so why worry?