If you live in the United States of America, Donald Trump is your president now. Unless you plan to do something incredibly illegal, there is no changing that fact. You can protest all you want, but it is very unlikely it will accomplish anything. However, I will respect your First Amendment right to protest peacefully. Given recent events, it seems like peaceful protests are becoming hard to find. There is no excuse to be physical towards the people you are protesting, counter-protesters, or people passing by who have nothing to do with your protest.
Hours before Trump was inaugurated, protesters smashed windows of businesses, like McDonalds and Bank of America, in anger and retaliation. Police in DC were in riot gear over the weekend to prepare for the oncoming protests. These acts of violence have caused protested to be treated more like riots than actual protests. More than 200 people have been arrested in DC alone for fighting with cops and other people. It's not just violence either. People have vandalized property and even set fires in the streets and formed blockades to disrupt the process. These reprehensible actions are a disservice to anyone else there to actually try and accomplish something through protesting.
I know not every person protesting Trump in DC or NYC will turn violent, but those who see it and do not intervene, or attempt to shield the aggressor, are just as bad. If you condone this, the cause you are fighting for will be painted in the same light as the violence and destruction it causes. It is of no benefit to anyone to be violent or make threats encouraging violence. It doesn't matter if you are protesting Trump, Milo, or anyone else, violence is never the answer.
It seems to me that peaceful discourse has become an endangered species. Instead of peacefully protesting and talking, we scream, fight, and riot when something doesn't go our way. Very few protests have remained entirely peaceful in recent memory, such as the insane dance party at Mike Pence's house. I don't believe it changed anything, but at least no one got hurt and nothing was destroyed. Why can't we discuss such controversial topics peacefully? We just can't seem to listen to one another. We only want to hear ourselves.
If you are planning to join a protest anytime soon, please remember to be decent. If you see something wrong, say something. Don't ignore it just because it was "for" your cause. Violence begets violence. That was something I thought we were all taught many years ago.