Shezanne Cassim, 29, of Woodbury, Minn., told reporters that he did nothing wrong and that there was nothing illegal about the video.
"I was tried in a textbook kangaroo court, and I was convicted without any evidence. So to me, this verdict is meaningless," Cassim said after arriving at the Minneapolis-St. Paul International Airport. He said that his ordeal shows the UAE is "scared of democracy," and that the government used his case to send a message.
"Imagine if you do something that's actually critical of the government," he said. "It's a warning message. And we're scapegoats."
Cassim was arrested in April and had been held at a maximum security prison in Abu Dhabi since June. Cassim said he and his co-defendants had no idea what they were accused of and waited months before they were told why they were arrested.
The UAE-owned daily newspaper, The National, has said Cassim and his co-defendants were accused of defaming the country's image abroad. Cassim's supporters said he was charged with endangering state security under a 2012 cybercrimes law that tightened penalties for challenging authorities.
He and seven others were convicted in December. Cassim was sentenced to one year in prison, a fine and deportation. The U.S. State Department said he got credit for time served and was given time off for good behavior.
U.S. Sen. Amy Klobuchar, D-Minn., who advocated for Cassim's release, spoke to Cassim by phone after his arrival and welcomed him home. She said his return was "long overdue."
"This guy has been waiting nine months for doing nothing but posting a joke video," Klobuchar told The Associated Press in a telephone interview Thursday. "It was simply a parody video poking fun at teenagers in the suburbs."
Susan Burns, the family's attorney in the U.S., said UAE prison officials escorted Cassim to an airport in the UAE on Wednesday, where he was reunited with his father and put on an airplane.
Burns said the ordeal has upended Cassim's life and the lives of his family members.
"You can imagine the torture they've been under for nine months, not knowing if they were going to see him, when they were going to see him," Burns said. "There's been a lot of anxiety ... mostly due to the arbitrary procedures over there and the lack of transparency."
Cassim said he was never physically abused, but was cut off from all access to media. He described his ordeal as living "pretty much in a cage." He declined to elaborate further.
Still, Cassim couldn't resist some humor, telling reporters his incarceration contained one positive: It broke him of his "ice cream addiction."
State Department spokeswoman Jen Psaki said Thursday that U.S. officials visited Cassim regularly, including as recently as Wednesday, before he was released.
"We were deeply concerned by the verdict," Psaki said. "We expressed concerns about the fact that he was arrested to begin with, but obviously we're pleased that it's been resolved."
Cassim, a U.S. citizen, was born in Sri Lanka and moved to Dubai for work after graduating from the University of Minnesota in 2006. He became the public face of the defendants after his family publicized his months-long incarceration.
Authorities in the Middle East have been cracking down on social media use over the past two years, with dozens of people arrested across the region for Twitter posts deemed offensive to leaders or for social media campaigns urging more political openness.
Cassim's documentary-style video, titled "Ultimate Combat System: The Deadly Satwa Gs," is set in the Satwa district of Dubai. It opens with text saying the video is fictional and is not intended to offend.
The video pokes fun at Dubai youth who style themselves like "gangstas" and shows fictional "combat" training that includes throwing a sandal and using a mobile phone to call for help.
Burns said the UAE enforced its law arbitrarily.
"To me it has been an incredibly frustrating experience trying to get this young man released for an innocent posting of a video," she said. "At the same time, the fact that he's coming home is a really, really good thing."
Cassim said he will not return to the UAE and, overall, he feels great to be home.
"I have access to Burger King again, so that's a big plus for me," he joked.
Associated Press writers Deb Riechmann in Washington and Jeff Baenen in Minneapolis contributed to this report. Follow Amy Forliti on Twitter: http://www.twitter.com/amyforliti