That's absurd. You'd be doing more to restrict people caught texting while driving than those that have been convicted of DUI or other more significant infractions. Plus, every douchebag with a chip on his shoulder would call the number and report the person whether they were texting or not, just because they didn't feel the person had their signal light on far enough in advance of changing lanes. Those calls would have to go somewhere, and chances are there'd be thousands of offenders with those stickers on their vehicles, so now you're talking about building a new government dispatch center to manage these reports, plus dispatching on them to investigate. That's assuming you wouldn't have these calls burdening existing 911/emergency dispatch centers (please tell me you wouldn't). Police departments would be too busy responding to "OMG SHE/HE'S TEXT MESSAGING AGAIN!" that they wouldn't be able to respond to nuisance false burglar alarms and other useless things that distract them from fighting crime. And granted it would be "easy to prove" someone was texting, but not without subpoenaing their cell phone records, which means now we would have to burden the justice system as well. I hope you're not a politician.