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
Thanks bro for the advice. I also have the hash tags you mentioned but my account was never blocked. It means I have to quickly remove it then to avoid issues with Twitter.