The Mastodon instance at which I'm a donating subscriber has a 12,000 char limit. And they block CF AI datafarmer bots. It seems quite trivial to block NSFW there, and it hasn't got any designated special-interest allegiances:
from https://hear-me.social/about
hear-me.social "is a general-purpose Mastodon server administrated in the Greater Boston, Massachusetts area. All are welcome to sign up, so long as the rules are followed.
"We federate with Threads, some do not. Read our Threads FAQ.
"We use Cloudflare to block artificial intelligence (AI) bots, crawlers, and scrapers from scraping your content for training large language models (LLM) to recreate posts without your permission.
"While most Mastodon servers are limited to 500 character posts, here posts can be up to 12,000 characters because we think you have important things to write.
"We also relay with over 1,500 other servers, some very large. This means we share each other's posts and accounts in real time. Your posts go to those servers immediately, even if there are no follow relationships. Servers without relay relationships only share posts when there are follow relationships. Your audience is large here, and you see more posts than you would on servers that do not relay.
"You can see the incoming messages arriving here from all over the Fediverse from the relay by going to our Live feed
"We do not secretly shadow-ban our own users ("limit" or "silence"). We will always notify the account owner of the action and the reason.
"When signing up, you must read the quick, short, set of rules presented to you. Requesting an account is confirmation that you have read and agree to abide by our rules..."
Their attitude is so great that I'm proud to donate, rhyme unintended, and I'm not usually too much of a donor guy. I just do a monthly coffee. They do not beg in any way. As far as I know it's just one guy, spending a lot of his own time & money on the Mastodon server as well as the PieFed instance from which I'm posting, and a Pixelfed instance, and a BlueSky PDS.
Just curious whether that's a word limit or character limit. Generous in either case, relatively. That's a lot of words.