Remember blocking and jamming are different.

I think you will find that the cell phone companies and thus the
government can block any group of numbers or specific repeaters
easily.

Cell phones do not talk to each other directly so interrupting service
should be a relatively easy matter as far as those with the know how
and authority to do so.

I would think it would be very much like blocking, or black holing a
group of IPs at, or through a specific location or locations.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com