That said, we already know they're trying their damnedest to track just that.
For instance, in my state and/or township one can go to township office and request a copy of all the property taxes for any piece of land, no matter who owns it. It costs something like ten dollars and in return you get a hardcopy with a bunch of numbers on it.
Assuming the process for getting copies of new permits is similar, the biggest downside is cost for the information and paying for some intern or whatever to type it in. Even if it's five dollars plus intern is decent chunk of money (I have no idea what the profit margin is on lumber, etc). And then you have to factor in the cost of the promotion which will eat into yet more profits.
Planning applications are available for viewing at the local planning office but they are not available online (though I know a guy who works at the local council who is pushing for them to put all their data online as part of the open government initiative so change is slowly coming here).
Such as when they file a building permit request. Which I suspect may be public information in many jurisdictions.