Lots of good answers here already. I’ll just add that Jon Stewart recently did a great segment that touches on this. Basically, he says if everything the government does is “OmG nAzIz FaScIsTz TrAiToRz!!!” then people who aren’t already paying attention will continue tuning it out. I forget at which time in the video he gets to this point, but honestly the whole 20-minute video is worth a watch.

Is there some way of safely circumnavigating these types of blocks in countries under oppressive regimes? I know about VPNs and TOR, but are those methods actually safe?

You’re mixing multiple subjects here, one being the logistics of blocking a federated system like Lemmy, the other being whether the wrong person finds the content of such a system objectionable and labels it a “national security issue.”

I’m being a tad pedantic here, but my reason for pointing this out is that I think #2 is not far fetched at all, but I’m unsure of how feasible #1 might be and would love if somebody who knows more than I do would chime in.

EDIT: Looks like some have already discussed #2 in the other comment thread started by Teknikal.