"This tweet is unavailable."

[RiotAndAlarum]

Does this mean I'm now on some sort of block list, or just that some tweets have been deleted? These are threads about contentious issues, so I could understand either possibility. Does anyone know?

You're blocked. Log out of twitter and go back to the thread, you'll be able to see them.

Three reasons: the tweet has been deleted; the tweet was made by someone who has a protected account (you will have to send the person a follow request if you want to see their tweets); you are blocked by that person, as mango says.

I've tried using twitter while not logged in, and sometimes there continue to be "this tweet is unavailable" spaces in threads, which I suppose could mean lots of options 2 and 3, nettie. It does seem to have escalated enormously after just two GC re-tweets and two GC comments (mixed in with some other stuff related to the original purpose of the account). How hair-trigger is that?!

I know! Apart from the people using the horridly named ‘terfblocker’ list, some people check what tweets you’ve liked and who you follow. I have been blocked by the world champion cyclist, Glinner obsessed Aidan & quite a few more.

This happened to me after I replied to a Tweet that linked in Caroline Criado Perez (though it was a point about academic research methods) and also commented about a rape case. I've Tweeted nothing GC or controversial yet I am blocked from many accounts.

...the world champion cyclist...

Laughed Out Loud at that!

I was on block lists before I had even tweeted. I think the algorithm uses who you follow, so you don't need to say anything, just follow the wrong people. Or right people.