Data mining in RFID?

I have been wondering what would be the status of data transmitted from RFID spectrum. That is considered as data mining too. Such data mining research should also take into consideration the unclear position in RFID. Especially, the legality of data that has been transmitted via the spectrum. I have stumbled across quite an interesting data mining research group here: http://dm1.cs.uiuc.edu/. Am awaiting whether such research effort is being done to ascertain the legality of RFID in data mining - whether it's purely illegal or whether it involves levels of intermediaries' consent.