A "perverse downstream consequence for debunking... being corrected by another user for posting false political news increases subsequent sharing of low quality, partisan, and toxic content".Looks like evidence for the backfire effect: "Direct correction ... backfires by making people feel defensive or focusing their attention on so…

"it would be useful to see if an account is a repeat offender or has been repeatedly labeled".Research undermining the backfire effect is now leading Twitter to a "more obvious" label design, and are exploring virality prediction to help speed up labelling. Difficult to assess effectiveness - insufficient public data.