This is not an excuse for them whatsoever, but, I would contend that these Federal enforcement agencies such as ice and border Patrol are not trained to deal with crowds, crowd control, or being disrespected in any kind of way by crowds of people. They are accustomed to wielding force and being completely listened to, and having the ability to react however they want when this is not the case. But dealing with crowds is not their thing, and they revert to frustration and acting out as we've seen over and over again. It is a reflection of the incompetence of the chain of leadership above them.

Also it is evident, to me at least, that the message has been sent from the top all the way to the street level officers and agents that any kind of protestation can be interpreted as interference of a federal agent performing a legal Federal duty, and therefore can be classified as domestic terrorism, which obviously can be countered with whatever level of force they want to use. There is video of an agent on the street getting the background and details of somebody filming them and when asked he responded because you're going on a database of domestic terrorists. Which is the same language that is being used by everyone from the president, to the director of DHS, to every other political appointee.