The other threats pertain to the rather complex issue of monitoring trunked systems. For straightforward conventional VHF or UHF frequencies, I get much better performance from using a commercial VHF or UHF handheld than with a scanner. Also things like priority scan work better. The disadvantages are (at least with Motorola radios) you can often only scan 15 or 16 frequencies at once, and unless the radio is field programmable, you cannot add frequencies on the fly.