Their armored vehicles are proof against rifles and .50 BMG rounds, but that's about it. Even against surplus M113 anyone here who bought books at gun shows back in the 90's and not retarded could come up with ways to defeat them.
ATF and I'd bet some other non Defense Dept. federals have Bradleys, and that's a tougher beast to take out. Armor is still made of aluminum but 25mm Bushmaster autocannon, TOW missile launchers, coaxial 7.62 can lay down a lot of firepower so you'd have to choose where you engage those much more carefully(hint, not in open country).
I'm not impressed with the Stryker. I don't care if they mount a 105mm cannon on one so long as you can lure those bus sized vehicles into crowded terrain they shouldn't be too much if you prepare.
What is worrisome are the upcoming generations of robotic weapons systems-the enemy will consider them expendable so long as they can produce and deliver them onto the battlefield and they WILL supplant the thinly armored target vehicles. Easier for some 400lb nerd with a big gulp in one hand, joystick in the other to play a real live version of Modern War on you than send a SWAT team with that hundreds of thousands of dollars of investment and years of experience...
Those will require a longer view war of sabotage and attrition, a strategic view of cutting off resources and supplies to the factories and urban areas to make deployment and expenditure costs of the robots too expensive to replace humans.