My father, Isaac, wrote this post.

As a young man, I was very involved in the antiwar movement, as well as other social justice causes. I went to many demonstrations, organized some, and spent two weeks registering African American voters in Natchez, MS during one Spring Break (I wasn’t smart enough to go to Fort Lauderdale). Like President Obama, I was trained by the Industrial Areas Foundation (IAF) as a community organizer and spent over a year working as a community organizer in a low-income African American neighborhood. You can read about my background as a true-believer radical at the link.

While I long ago hung up my demonstrating spurs, looking back over four decades to my activist and community organizing days gives me an unusual perspective on the sudden eruption of large street demonstrations by the Resistance to Trump.* This is my guide to Resistance fighters, who are willing to leave their coffee shops, yoga studios and Whole Foods for the suddenly trendy act of street demonstrations.

Not everyone in the thousands of people marching will necessarily share your desire for the peaceful exercise of group free speech. Some demonstrators likely have ulterior motives, whether they be the black masked anarchists who seem to love to break Starbucks windows, or, potentially much worse agent provocateurs. Such infiltrators could be aligned with some interest group, which could include Trump supporters, police—or, I suppose, even Putin, if you’re a conspiratorial sort.

As the protests grow, local cops and politicians, including Democrats, are going to be under increasing pressure to contain demonstrations to enable people to get to work, etc. It only takes a few agitators to turn a peaceful march into a riot. I know this first hand, as I was part of a demonstration of about 5,000 students protesting a speech by then HUD Secretary George Romney that suddenly turned ugly. Within a few minutes, some people in the crowd starting taunting the police and rushing the stage where Romney was speaking. A later investigation found that the people who rushed the stage were actually police agent provocateurs planted in the march. Waves of baton wielding cops moved on us from all sides. Tear gas canisters went flying. I got fairly badly tear gassed and retreated to a nearby classroom building to hide in a bathroom and wash my eyes, which is a different meaning for “sheltering” in place and a different meaning than today’s “safe space” advocates have in mind.

In a large march or demonstration, you’ll only see what happening immediately around you, and you can quickly get caught up in a riot without realizing that a riot is happening. Always be aware of your surroundings and who’s nearby.

Try to give yourself an escape route and be prepared to bolt. This is not the time for flip-flops and t-shirts. Wear running shoes, long pants, and a long sleeved shirt, since tear gas and CS gas (much stronger than tear gas and sometimes used by police), irritate the skin as well as the eyes. Carry a hanky and water bottle in case you need wash your eyes out if you get teargassed. Above all, resist the urge to get in the face of cops, throw projectiles or otherwise provoke police—they will use their batons to defend themselves and you might easily be handcuffed and carted off to jail.

Leave your babies, kids, and dogs at home. While pushing a stroller makes for great TV/Facebook/Instagram videos, kids and pets will be in extreme danger if a riot develops and you won’t be able to protect them.

The biggest danger is that counter-marchers will appear. So far, the Resistance marchers have had the field to themselves. Eventually, counter-marchers will start showing up. Over 60 million Americans voted for Trump and they also know how to use social media. Two opposing groups of peaceful demonstrators are not a problem, and police will usually try to keep them separated.

But just as there are anarchists aligned with the Resistance, some pro-Trumpsters may show up with ax handles and be intent on mayhem. Trump has fairly strong support among police unions, veterans, and bikers, for example, and these guys may show up ready to fight.

The police rank and file may also be more sympathetic to the counter-marchers than the Resistance and might just let the two groups tangle for a while. Or the police themselves can become the counter-marchers, like the Chicago Police Department at the Democratic Convention in 1968, which was later deemed a “police riot.” I don’t think any cops were disciplined, but hundreds of demonstrators were badly injured and the Chicago Seven faced years of litigation.

The free expression of political opinions is the bedrock of the American democracy and I’m all for showing opposition to the politics and politicians of the day. As the Rollings Stones said in “You Don’t Always Get What You Want,” “And I went down to the demonstration to get my fair share of abuse.” Don’t needlessly open yourself to abuse.

* I think conjuring up images of WW II France is overwrought, unless volunteers from Brooklyn and Santa Monica are going to parachute into coal country and disguise themselves by wearing red Make America Great hats, chewing tobacco, and driving Ford F-150s. If I were a community organizer on this project, I would use the term “Rebel Alliance” instead. The French Resistance were all white folk, while Star Wars goes for ethnic and inter-planetary species diversity.