Editor's Note: (James A. Gagliano is a CNN law enforcement analyst and a retired FBI supervisory special agent. He is also an adjunct assistant professor at St. John's University in Queens, New York. Follow him on Twitter: @JamesAGagliano. The views expressed in this commentary are his. Read more opinion on CNN.)

(CNN) Nothing quite exemplifies "tolerance" like the video of masked young people hurling objects and screeching profanities at a young, conservative journalist.

James Gagliano

The viral images are sickening. Andy Ngo, a photojournalist and editor at the online magazine Quillette, who has made a cottage industry of exposing instances of manufactured hate crimes, was viciously assaulted while covering an Antifa rally held as a counter-protest to a rally of right-wing groups, including the Proud Boys, in Portland, Oregon. "Antifa" derives from "anti-fascist," and is associated with aggressive, hard-left activism. The video shows masked protesters circling Ngo, punching and hitting him and dousing him with a "milkshake," then following him as he flees. One hurls something at his back.

Too often, we are seeing these days an abrogation of civil decency, a proliferation of anarchy and lawlessness. Regular, and potentially lethal, violence by masked-protester assailants is too often excused and condoned by Twitter-warriors. This must not be our new normal.

Simply bearing a name that says you're opposed to evil, like anti-fascist, should not inure us to your unprovoked violence and unconstitutional attempts to block others' free speech rights. Everyone, right and left, must condemn and literally unmask this behavior -- not glorify it for political ends.

As CNN's Jake Tapper observed on Twitter: "Antifa regularly attacks journalists; it's reprehensible."

Ngo also made several posts to Twitter following the assault, during which, he said, his camera equipment was stolen. Ngo posted photographs of his bruised and battered face taken, he wrote, from the emergency room. His lawyer claims Ngo suffered a "brain bleed" from the assault. Jim Ryan, a reporter for The Oregonian chronicled the competing rallies by protestors from the left and right, as well as the attack on Ngo.

According to Ryan, police said that some of the masked goons may have laced their favorite milkshake projectile with "a substance similar to quick-drying cement." And so, a conservative journalist received his -- in the view of these radical left protesters -- "just desserts."

It is no secret that in the post-Ferguson era of policing, many in law enforcement are worried about being accused of "provoking" protestors -- even those who break the law in plain view of uniformed police. Former FBI director James Comey described this phenomenon as the Ferguson effect or viral video effect.

We exist in a structured, civil society, where lawful protests are considered one of the foundations of our nation. But some organizers ignore current laws from the get-go by failing to comply with a requirement to obtain a permit (the Portland Mercury reported that antifa protesters did not have one). The right to gather and protest is not an absolute. Under the constitution, the Supreme Court has found, we all have the right to peaceably assemble, provided a permit is secured in advance, and all local laws are followed that mandate when and where the protest may take place.

Too often, protestors of all stripes ignore these laws -- choosing to mobilize via online appeals without involving government officials in their plans. Or they defy the terms of their permit when a protest gets out of hand.

What's more, for many of the current crop of young protesters, like some of those in Portland, attacking an unarmed journalist whose views they abhor is somehow noble and carries with it the breathtaking exhilaration of anonymity -- courtesy of a face scarf or mask. Much simpler, when so adorned, to get away with saying and doing things that might arguably draw charges of incitement to riot.

And though some states have over the years criminalized the wearing of masks used to evade or escape discovery of one's identity when gathered in groups or committing a crime, some have curiously chosen not to.

Anti-masking laws are nothing new. An 1845 New York State law was a response to a dispute between land-owners and tenant-farmers who worked their land. New York City later grappled with this law during the 2011 Occupy Wall Street clash with protestors -- some masked -- who took over a public park. At least five Occupy protesters were cited for violating the law then, according to Joe Coscarelli, writing in New York magazine.

There is no question: masks afford anonymity. And so, since political protests might turn into confrontations with police or counter-protestors, why should we not strictly forbid their usage in these instances? Certain restrictions should not be considered unconstitutional impingements on free speech.

One resonant example I think we can all get behind? In 1990, The Georgia Supreme Court reinstated a 1951 state ban on the KKK's hood-wearing during the Jim Crow era. To be sure, antifa is not a movement on the malignant order of the KKK, but we need to recognize that the principle is the same: when particular groups are predisposed to violence, we have an obligation to strip them of their anonymity. And for those who claim their mask must be viewed as constitutionally-protected free speech, recall the late journalist and social commentator, Nat Hentoff, who aptly described this affliction as "free speech for me, but not for thee."

So, if we demand our alt-right and neo-Nazis gather sans face-covering, then that edict should apply to counter-protestors like antifa as well. To consider anything less would be unconstitutional.

Also keep in mind that masked anonymity shields provocateurs and protects them from identification and subsequent prosecution for criminal acts -- like the assault on Andy Ngo. Unmasking these miscreants better positions society to hold them to account. Or in the immortal words of early 20th century Supreme Court Associate Justice Louis D. Brandeis -- "Sunlight is said to be the best of disinfectants."

Let us cease viewing this issue as too complicated. It really is not. While some minimize assaults like the one on Ngo because the assembly may have been "mostly peaceful," this risks tacitly condoning the behavior of those in the group who are prone to violent acts. Making excuses for violence because the offenders are adherents to your particular political views makes you a partisan apologist and a hypocrite.

Of course, many conservatives act as "Trump apologists," covering for the President when he says or does something worthy of criticism, and they tolerate the intolerable in the pursuit of more conservative Supreme Court appointments.

But equally infuriating is the progressive left's pretending that elements of the antifa brigade are not violent anarchists. Supporters of antifa will argue that protestors wear their masks—their "black bloc attire"-- as an act of solidarity and to avoid being doxed. Violent protesters should remain unmasked. There is simply no reason not to enforce current state anti-masking laws. And maybe it is time to discuss the enactment of a federal law to be evenly applied across our great nation.

If one's purpose is to peaceably counter-protest or rally for a just cause, what would be the concern with showing your face?