You should watch who posted this and consider banning them from the reddit community. This is advising people to make themselves victims for police to beat up more easily.
Helping police arrest people, what the heck is wrong with you? If these are agent provocateurs planted by the police what will happen is police will ignore them, beat the crap out of everyone else to instigate the violence they want and if necessary beat the shit out of nearby journalists and destroy the evidence. Then they will make a press release that will be parroted by all Trump aligned media how they have been attacked and needed to use force. The people who sat down will be painted as obstructing police and there will be claims like they would have pulled officers down by the legs or similar.
When police starts attacking you close the rows hook under and seek to create cover against incoming projectiles.
Also if you think you wouldn't be among the people beaten up because you are a good white middle class person, or family with kids or elderly, here is a video of cops tossing an elderly professor around last year.
https://www.newsweek.com/65-year-old-man-lucky-alive-after-arrest-campus-protest-1895846
or what about causing an elderly men brain injury during BLM protests and then being cleared of all charges?
They will beat the shit out of you and then you will be blamed for it. Oh and good chance your insurance will not cover your injuries if police paints it this way. So aside from having the crap beaten out of you, you will also be brought into financial jeopardy.