I think bringing a rifle to a peaceful protest is horrible and the fact that it is happening is a sure sign that the time when this could be fixed with peaceful protests is long past. The way I see it there are only four possible reasons to bring a rifle to a protest and only one is even vaguely ok. 1. The most benign would be if the protest is about firearms/2A and the rifle is totally symbolic. 2. You intend to threaten or intimidate with an implied threat of violence. 3. You fear physical violence either from counter protesters or from law enforcement and bring it for protection 4. You intend to commit a violent act. None of these seem to be in line with a peaceful protest. With #1 I think the symbol could be representational rather than a real firearm and is more in keeping with a peaceful protest. With #2 and #4 you are not really intending a peaceful protest. And with #3 you don't really expect a peaceful protest and are coming prepared for something else. The bottom line here is that the current atmosphere around protests in the US is driven by #3. Police do not show up in normal patrol uniforms... they come in full riot gear right from the beginning. For decades peaceful protesters have been getting beaten and pepper sprayed in the face. The police only have themselves to blame for the fact that protests have stopped being 'peaceful protests'. Routine police brutality (#3) has lead directly #2 and #4 because protesters assume there is not really such a thing a 'peaceful protest' anymore. Escalation happens.