"It definitely put a little bit of conflict out there. We definitely have received a lot of feedback on it, calls and e-mail," said Trooper Cameron Roden, a spokesman for the highway patrol.
The video, taken from Trooper John Gardner's patrol car, shows him using his Taser after Jared Massey refused to sign a speeding ticket Sept. 14 and walked away from the officer on U.S. 40 in eastern Utah.
Massey shrieked and fell after he was hit and then asked Gardner, "Officer, I really don't know what you're doing."
"Face down! Face down! Put your hands behind your back," Gardner said.
When a woman emerged from Massey's vehicle, the trooper ordered her to get back in - "or you're going to jail, too."
Moments later, when another officer arrived, one of them said, "Oh, he took a ride with the Taser."
In an interview with CBS Early Show Co-Anchor Harry Smith, Massey described the sensation of being zapped by the instrument.
"Fear, panic - it's the scariest moment of my life," he said. "I get tasered, and I hit the ground, and I really, to be honest with you, thought that my life was ending. It's the most horrific thing that's ever happened to me."
Utah Highway Patrol Spokesman Sergeant Jeff Nigbur told Smith that he could not comment on whether the trooper's conduct in the video was standard operating procedure.
"We have an internal review process happening right now," he said. "We are going to look into whether the officer's actions were appropriate or not."
Tasers use compressed nitrogen to fire two barbed darts that can penetrate clothing to deliver a 50,000-volt shock to immobilize people.
"I can't speculate on what was happening in the trooper's mind," Roden said. "We have an internal investigation going on. ... With it coming out on YouTube, we have expedited the investigation."
The 10-minute video landed on YouTube after it was released to Massey under a public-records request.
Signing a speeding ticket is not an admission of guilt, Roden said. He described it as a promise that a motorist "will take care of the citation."
Under UHP policy, a Taser can be used if someone is a threat to themselves or others and other means of control are unreasonable, the spokesman said.
Massey has filed a complaint with UHP, said Roden, who didn't know the status of the speeding ticket.