Dharun Ravi was found guilty of all 15 charges against him, including invasion of privacy and anti-gay intimidation. The jury decided that he not only spied on Tyler Clementi and another man as they were kissing but also singled out Mr Clementi because he was gay.
Mr Ravi, 20, could get up to 10 years in prison by some estimates and could be deported to his native India even though he has lived legally in the U.S. since he was a little boy.
The case stirred a national conversation about anti-gay bullying and teen suicide. It also illustrated the dangers of technology in the hands of people who have grown up with the likes of Twitter and Facebook.
"They don't feel like they're spying. It's just their own iPhone they're using, their own laptop," said Annemarie McAvoy, an adjunct professor at Fordham Law School in New York. "Hopefully, parents will use this as an example for their children."
On the Rutgers campus, student Melvin Ways said: "I think the lesson here is not everything is meant to be publicised to the entire world, especially private matters and things that are personal to people."
Prosecutors said Mr Ravi set up his webcam in his dorm room and watched Mr Clementi kissing another man on September 19, 2010, then tweeted about it and excitedly tried to catch Mr Clementi in the act again two days later. A half-dozen students were believed to have seen the live video of the kissing; no video was taken in the second instance.
On September 22, Mr Clementi threw himself off the George Washington Bridge after posting one last status update on Facebook: "Jumping off the gw bridge, sorry."
At a courthouse news conference after the verdict, Mr Clementi's father, Mr Joe, addressed himself to college students and other young people, saying: "You're going to meet a lot of people in your life. Some of these people you may not like. Just because you don't like them doesn't mean you have to work against them."
Mr Ravi shook his head faintly after hearing the verdict. He and his parents left the courthouse without comment, his father's arm around his shoulders.
His attorney Steven Altman issued a brief statement saying "everyone could rest assured that at the appropriate time an appeal will be filed."
Mr Ravi's lawyers had argued at the trial that the college freshman was not motivated by any hostility toward gays and that his actions were just those of an immature "kid."
In letting the case go to trial, Mr Ravi gambled and may have lost big. Months ago, he and his lawyers rejected a plea bargain that would have spared him from prison, and prosecutors would have even helped him avoid deportation.
The most serious charges - two counts of bias intimidation based on sexual orientation - carry up to 10 years in prison each. But legal experts said the most Mr Ravi would probably get all together at sentencing May 21 would be 10 years. The judge could also give him no prison time at all.
Prosecutors said they would consult with Mr Clementi's family and the other man in the video - identified as only as M.B. - before recommending a sentence.
Mr Ravi was also convicted of seven counts of covering up his actions by instructing a friend what to tell investigators and deleting tweets and text messages.
He was not charged with causing Mr Clementi's death. And while the jury was told Mr Clementi had taken his life, prosecutors did not argue directly that the spying led to his suicide.
Mr Clementi's death was one in a string of suicides by young gays around the country in September 2010. President Barack Obama commented on it, as did talk show host Ellen DeGeneres.
New Jersey lawmakers passed an anti-bullying law in the aftermath, and Rutgers changed its housing policies to allow people of the opposite sex to room together in an effort to make gay, bisexual and transgender students feel more comfortable.
"The verdict today demonstrates that the jurors understood that bias crimes do not require physical weapons like a knife in one's hand," said Hayley Gorenberg, deputy legal director of the gay rights organization Lambda Legal.
Some of the jurors said that Mr Ravi's tweets, especially one that "dared" friends to watch the webcast that never happened, were key evidence in convicting him of anti-gay intimidation.
"That post, what it said, struck a chord in all of us," said Ed Dolan, a finance manager.
Another juror, Kashad Leverett, a security guard, said that Mr Ravi's videotaped interrogation by police also helped convince jurors of his guilt. "He admitted to it, saying, 'I knew it would embarrass him,'" Leverett said.
Mr Ravi and Mr Clementi, both 18-year-old freshmen from comfortable New Jersey suburbs, had been randomly assigned to room together, and Mr Clementi had arrived at college just a few days after coming out to his parents as gay.
A line of students testified they never heard Mr Ravi say anything bad about gays in general or Mr Clementi in particular. But students did say Mr Ravi expressed some concern about sharing a room with a gay man.
On September 19, according to testimony, Mr Clementi asked Mr Ravi to leave their room so that he could have a guest. Later, Ravi posted on Twitter: "Roommate asked for the room till midnight. I went into molly's room and turned on my webcam. I saw him making out with a dude. Yay."
Mr Ravi told police that he watched only seconds of the encounter. His friend Molly Wei testified that she and a few other students also watched the live stream of the men kissing. (Wei was initially charged in the case but cooperated with prosecutors and will be allowed to keep her record clean.)
Two nights later, Mr Clementi asked for the room alone again. This time, Mr Ravi tweeted: "I dare you to video chat me between the hours of 9:30 and 12. Yes, it's happening again." He also texted a friend about a planned "viewing party" and allegedly went to friends' rooms to show them how to access the feed.
However, there was no evidence the webcam was turned on that night. Mr Ravi told police he had put his computer to sleep. Prosecutors argued Mr Clementi himself unplugged the computer.