Now there are massive blocking of Twitter accounts.
Most often, block accounts when you to use mass-following. Blocks is forever!
Also do not use hashtags #ICO #Cryptocurrency etc
Be careful!
UPD
Some accounts of my friends that have been blocked marked "forever" are now unlocked
But anyway, I think we need to be careful
I got a ban. I do not lead the company twitter. But I announced my YouTube videos. For what was now blocked. Perhaps this is temporary. But it is better not to announce your videos.