Elected official blocking social media users violate the 1st amendment

I think it's pretty clear. It's your content AND you give them the right to use it royalty free... (as an aside, this is an issue that does need to be addressed at some point - data is enormously crucial to businesses of all sort, not just social media, and continue to increase in value, yet the collective world wide users are "forced" to give them away for free... users should get a slice of it).

Whatever the EULA, it wouldn't by-pass copy-right laws. So I think what's "muddy" is related to copy-right protection - what tweets actually can qualify as being copy-right-able.

I agree with the Court opinion based not on who own the content, so that's not too important to me. It's more about government official using platform (even if private) for official work while excluding certain voices. I think it's a pretty straight forward common sense opinion. There is a pitfall to this, in that technology allow a few voices to crowd out all voices - however, this can be handled by laws, similar to those that handle DoS attacks.