1. I’m seeing uninformed commentary online from people who think that the use of a fake suicide vest in the London attack today must mean this wasn’t a terrorist attack. In fact ISIS has pushed this very tactic, sharing tips on how to make fake vests. 
2. Numerous other known ISIS-linked attacks included the use of a fake suicide vest, including the former London Bridge attack in 2017; in the Barcelona / Catalonia attack that same year; and in several in France.
3. What’s the purpose of the fake vest? Quite simply it’s to provoke suicide-by-cop. In ISIS’ lingo, this helps ensure their guy is “martyred.” More practically it also means he’s less likely to get caught which may result in him revealing details about the network he belongs to
4. The @metpoliceuk has called the attack terrorism though of course it’s early hours & things can always evolve as new information appears. One element that may be missing for a while — an ISIS claim. A few days ago, @Europol successfully booted ISIS’ off of the app Telegram
5. Law enforcement has tried to do this before and I’ve received valedictory press releases in years past claiming to have shut down ISIS’ ecosystem, only for ISIS to pop back up in a few days. So far this attack appears to have had an impact. Their channels are mostly down
6. So without it’s usual platform can ISIS prevail and still claim it, assuming they believe this is one of their own? Yes. But it might take longer. Meanwhile some of the slim pickings in the few ISIS-linked channels that are up:
