During the 1960s my dad worked at the Food and Drug Administration in downtown Seattle. During civil rights protests he would look out the office windows, down onto the protests and spot all the plain clothes FBI agents.
It was easy, because the FBI plain clothes dress code mandated agents wear trench coats and fedoras. Seattle is not, and never has been a formal wear as normal wear kind of city. The Feds stood out like sore thumbs then, just like the Patriot Front stands out now.
Some kinds of stupid never changes.
The government thought they were clever by dressing up their undercover Feds in what they assume was typical “rightwing” gear such as khaki pants and, above all, those dopey shields. Drummer boys for added effect on marches. Problem is the very uniformity of the Patriot Front with their dopey gear is an obvious giveaway. Oh, and not a beer belly in sight.