It's also frustrating that Twitter didn't proactively do this - the DCCC had to figure it out and tell them. Twitter itself is obviously best positioned to detect patterns of suspicious activity, intervene before too much damage is done, and investigate and publish their findings. But they don't seem to take this problem very seriously.

Twitter is being brazenly used as a propaganda tool by terrible actors with terrible agendas. It's infested with strange accounts of dubious authenticity - which I think is fairly obvious looking through the replies to prominent political accounts.