"Quick - someone get on a secure, anonymous, wireless TacNet system for motorists! Combination dashcam, GPS, radar detector, and data sharing."
Hmm...the judge only approved the expressive conduct, not radar detectors. Many states ban them, so you may be able to tell others about speed traps, but be limited in how you are able to detect them other than by your own eyes.
The commuter map app Waze allows people to report both visible and hidden cop cars on roads - I don't know if that feature is still available now that Google owns it. So we already have the tacnet.
(I'm not in favor of speeding, mind you, but a lot of speed traps are for quotas and profits. And many are set up at the bottoms of hills to snag anybody and everybody, not to get prolific speeders. I'd rather see tailgaters busted. )