When the System moves to MPSCS, they will be using Talk Group paging, the Unication 1.30 Firmware allows for an encryption key to be installed, so after they are fully transitioned, they are planning on EVERYTHING being encrypted. The logic, like it or not, is that FD usually responds to high profile incidents like shooting, stabbings, MVAs, ect. Therefor one could get information on were police are by this info.
In the meantime quite a few agencies utilize VHF and UHF patches for paging POC and Volunteer Fire Personnel