A few months ago, police were investigating a series of tire ("tyre") slashings in Hampshire, England ("England") that were apparently driven by a peculiar kind of phone rage: The slasher left a blackmail-style (letters cut from a newspaper) note reading, "Warning. You have been seen driving while using your mobile phone."
I've noticed "Hang Up And Drive!" bumper stickers but I've never heard of anyone tackling this problem quite so...directly. Since a driver on the phone is (as we keep hearing) more dangerous than a driver on the bottle, it certainly isn't surprising that someone's gotten mad as heck and isn't going to take it anymore--perhaps (s)he was the victim of a road accident caused by a yammering motorist. That is not the point, however. The point is that the perpetrator apparently has easy access to England's motor vehicle database (MVDB) and isn't afraid to use it.
An MVDB is a dangerous thing to leave lying around, for reasons the cellular vigilante amply demonstrates. Here I'll do my usual scale-up ("if everybody had it") analysis: What if a service called MVDB-Lookup (which for all I know is already a Silicon Valley start-up with two rounds of funding) let you get a name and address just by texting in a registration number?
We tend to have a feeling of invulnerability in our cars and at the same time tend to "become" them--we say, "he rear-ended me!" rather than "his car rear-ended my car." So it would be fitting if your particulars could be easily derived from your registration plate by anyone who was casually curious. This would be a bad situation because (as you know if you spend any time there) the earth is home to many crazy persons--in particular, persons willing to extract disproportionate revenge for the slightest slight. And slights (deliberate or otherwise) are part and parcel of driving--even the most careful vehicle operator can't avoid giving offense once in a while.
On the plus side, MVDB-Lookup would let you hurl more personalized insults ("Only losers live in Long Beach!") at fellow motorists. However, it would also give numerous deranged drivers the tools they need to extract revenge for automotive sins real and imagined. So if you come home one evening to find your garbage cans tipped over and your cat soaking in Nair, you'll understand why. Further proof that the democratization of information isn't always a good thing. Drive safe.