It’s being reported that rioters in Portland have used lasers to blind, perhaps permanently, federal law enforcement officers who were engaging in riot control. If so, it was unwise.
IANAL, but IIRC, an attack that can cause an injury such as blindness is usually considered dangerous enough to justify a response that can include deadly force. The feds’ response so far has been limited to normal riot control techniques, so the rioters haven’t experienced much more than a whiff of tear gas. There is a wide array of more powerful tools available to deal with the rioters.
Some of the Portland rioters may be trying to goad the feds into opening fire with their firearms, seeking to sacrifice some of their fellow travelers as Kent-State-style martyrs. I doubt that will happen. The BORTAC team has a reputation for being among the best trained and disciplined in the business. They aren’t a bunch of green, young National Guardsmen who’ve never been in a skirmish before.
I suspect that an appropriate response is coming, and I’ll bet that Antifa won’t like it.