I could be misinformed, but couldn't a contractor or independent company just partner with government agencies (local, state, federal) and thus do away with the first amendment infringement issue?
IIRC, this is how some tech is exempt from FOIA requests (because the tech is "private" even though the end user is the DoD).
Allegedly they basically did that with facebook. The CIA venture arm in-q-tel[1] invested. Presumably they could do some loophole where a contractor runs a site that way but it would probably be a huge headache. Iirc there is a clause that governments cant compete directly with private enterprise, at least, the Federal gov.
IIRC, this is how some tech is exempt from FOIA requests (because the tech is "private" even though the end user is the DoD).