Always important to keep in mind that in a scenario where it's the police that are being protested, the arrestee's legal classification boils down to "he-said" "she-said" against state authority.
Second, sure they will be proven guilty because of the video evidence, however, criminals still have a right to privacy. A conviction in the US is effectively a death sentence, as in your life is over - your mugshot will do the rounds on the internet, any future employer will deny you, etc. If people's privacy was protected, they could rehabilitate and reintegrate into society once they've done the time. Not much of a chance of that in the current system.
Tell that to Bill Ayers.
By contrast, here's a database of people involved in far-right violence organized around the actual disposition of legal cases, with references to primary sources like court documents rather than shallow news articles.
All the information is public knowledge. You name, age, photo, and what you did in public is not a doxx. If their social security numbers, addresses, phonenumbers, or family members were listed it would be totally different.
If it was against people that weren't violent and didn't have convictions, I would feel different.