Well, be happy! We've had a little longer than most countries to monitor our public safety. Most countries already have encrypted networks in place (TETRA used by over 114 countries), the USA is just a little behind the times in that aspect. There will be a time in the future when we don't hear a peep out of ANY public safety. Sad, but true and a sign of the changing times.
TETRA is a TDMA digital voice/data standard developed in EU by their standards orgnization
ETSI. It is an "open" standard, that is, it is published. While it has encryption capability, that option is the choice of the user organization, just like in P-25 which was developed by APCO. Both P-25 and TETRA are international standards, both are published, and both can be licensed. As far as I know, a scanner maker can purchase a license to decode TETRA just as they do for P-25. The failure of scanner makers to do so is likely because of the lack of TETRA systems in the USA.
BTW, before they realized how poor a marketing name it was "TETRA meant Trans Europeran trunked radio" it was only when they started to realize they could make money outside Europe that the name became "Terrestrial turnked radio" !
Pleae note that TETRAPOL is something else, is not publised and is mostly used by Security Services.