(Reminder: bots can be human too. But they're paid propagandists. Block 'em if you see 'em!)
- old account, suddenly very active
- massive number of monothematic tweets
- small number of followers (sub 100 - you would expect more for accounts established for a number of years, and with thousands of tweets)
- impervious to logic
In the end it's gut feel.
Personally, I block 3 main types of accounts:
- bots
- posters who abuse me or swear at me
- obviously racist/offensive accounts
Does it help? Who knows. Certainly, *I* feel better afterwards!