The rapid takedowns are a sharp contrast with Twitter's former hard line on free speech. While it still tends to value freedom of expression as a rule (particularly in countries where Twitter restrictions are mainly used to stifle dissent), it's now eager to scrub tweets instead of waiting until officials step in. Twitter isn't the only tech company taking a more active approach -- talks with the US government have led to a broader anti-extremism push that includes Facebook and Google. However, its breakneck pace this time suggests that it may be one of the first (if not the first) to purge extremist material from now on.