That sounds like a perfectly reasonable application of existing law to new technology, something that the law (government & judiciary) is not usually noted for. Part of the problem seems to be that there doesn't seem to be a mechanism for preemptive legislation...........you have to wait for some defence lawyer to cry "foul" before you get a ruling?

On a somewhat related note, here is an article on "legal cell-phone surveillance"

http://news.cnet.com/8301-27080_3-20002986-245.html

I was somewhat surprised that it is apparently legal.