Trespassing? OK,I'll accept that. I've seen it suggested that many didn't even realize they were trespassing. But ignorance of the law,they say,is no excuse.
If we're talking "insurrection" we need to talk about firebombs being thrown at Federal courthouses in Portland,Seattle and elsewhere last year.
January 6th wasn't within 100 light years of being an "insurrection".
In this case, the defense against trespassing isn’t ignorance of the law, but rather ignorance of the fact that they weren’t permitted to be where they were. And that is a legally valid potential defense.
The Antifa/anarchist punks are probably the ones that did not get arrested. /s