That's good to know.The telecommunications Act of 1996 made it illegal to listen to cell phone frequencies, some older scanners can do that. Other that that and to other mentioned above you are good to go.
I suppose the older scanners were legal under the original communication act of 1934 that pretty much stated anybody can monitor any radiofrequency transmission, provided they do not tell others what they heard, nor use such information for personal gain. That law is pretty unenforceable, hence the later mods to it.