Back in the long-ago year of 1995 the U.S. government took a good look at the vulnerability of civilian federal office buildings to physical attack. (Read the report here.) In brief, the task force that researched and prepared the report recommended that the USG adopt a set of physical security standards that were closely modeled on the standards the State Department had created ten years earlier for overseas embassies.
Only, the overseas standards were thought to not be pertinent in all respects to the domestic threat environment, especially not to the threat of mob violence. After all, we'd had a large vehicle-borne bomb in the Oklahoma City attack, and that certainly looked exactly like overseas terrorism, but we hadn't had large mobs or other civil disturbances against domestic federal buildings in a very long time. [Pro Tip: look up the history of the 1919 General Steel Strike and the declaration of martial law in Gary, Indiana.]
So there was no need for our modern domestic building standards to require perimeter walls, forced-entry resistance, safe havens, or other such counter-mob defenses. That was just reasonable risk management.
Well, that reasoning was also from a very long time ago, and it no longer seems to apply to our new domestic threat environment. For instance, the ongoing riots against immigration enforcement in Los Angeles.
Speaking of which, check out that video above of a protestor banging away with a hand tool at concrete anti-ram bollards - which are a countermeasure against vehicle threats - in front of an ICE detention center.
Why was he doing that, you may wonder? Maybe because he wanted to create a pile of concrete shards that his fellow protestors could fling at the detention center. Or, just as likely, for no good reason at all but simply because it was a riot and he wanted to do something mindless and destructive.
Whatever his reason, he kind of perfectly exemplifies the contemporary threat to domestic federal civilian buildings, and it is something that our current facility security standards do not begin to counter adequately.
My prediction: you may expect to see hasty walls and fences going up around your local government buildings in the short term, and proposals for costly forced-entry facade upgrades in the mid and long term.