Hell yeah I would. Citizens duty to keeping the neighborhood safe.
This one time my buddy and I were really high and we were driving around. This bigass truck was driving alongside us, we were in the middle lane, he was in the left lane...and he eventually drifted further away from us, popped the curb, and went on the other side of the road. He was swerving all OVER the place. Could not control his vehicle.
In our stoned stupor, we were amazed at how drunk this guy was...so we called the cops. The operator instructed me to turn on my hazard lights, and I eased back and just kinda watched him do all this shit. He pulled over....got out, car still running, and stood in a front yard as I drove past, still on the phone with the operator...as I got a couple of car lengths away from him, he got back into his car, and started to follow me...stoner paranoia kicking in like I thought he was about to chase me down to ram my car or beat us up, I turned right...and FLYING UP ON US from the opposite end of traffic, was a local cop.
His window was rolled down he stopped, I stopped. I roll mine down, still on the phone, and he's like "WHERE IS HE." and I'm trying not to act stoned, I'm like "he should be turning from behind me any moment now." Sure enough, the truck creeps over and him and another cop CONVERGE on his ass.
The operator instructed me to wait at a nearby parking lot, where my buddy and I are laughing our asses off, talking about the superiority of being stoned as opposed to drunk. They call us over to where they pulled him over, we pretty much told the officer everything we saw, and he's like "Cool, this guy will getting a DUI."
Luckily, we're smart enough not to smoke in the car, or carry with us, but it was a really funny moment that I'll never forget. The vigilante stoners snitched out a drunk.