Yes, but not as much they would like. I won't list their accomplishments to not encourage successful OpFor messaging. Instead, I'll say that the VAST majority of their efforts are for their amusement and have no effect.
Sort of like drunk enemies shooting at a fort. 99.9% of the ammo is wasted. Every once in a while they'll get lucky and hit something, but we don't mention it so as not to encourage them and give them anything but false hope.