It was all in response to this tweet from the account #JLReunion, asking fans to tell Warner Bros. Home Entertainment to make a reunion film a reality. The tweet was retweeted nearly 5,000 times, including by some members of the cast, who now are speaking about the groundswell with Heat Vision.

“I'm often at Comic-Cons across the country where I get to interact with the audience, and a frequently asked question is why there hasn't been a Justice League animated movie based on the animated TV series," says Kevin Conroy, who has voiced Batman for 25 years. "There's a large and loyal fan base there that you'd think the studio would want to tap into. To me it's a no-brainer."

The Justice League series originally ran on Cartoon Network from 2001-04, and it was followed by Justice League Unlimited (2004-06). It continued the momentum Conroy started with Batman: The Animated Series and helped build the DC animated universe, which many of the comic book faithful consider one of the company's crowning achievements.

Celebrated animation director Andrea Romano has told the cast she would come out of retirement should a movie materialize, and the stars already have a few ideas of the kinds of stories they'd like to work on (though they say they defer to the writers and producers).

"Well, selfishly, I’d love to explore the relationship between Bruce and Diana a bit more, and I know there are some wonderbat fans out there who feel the same way," says Wonder Woman actress Susan Eisenberg. "But mostly, I would just love to see a story where The League is united in its fight of good vs. evil, with some romance and levity thrown in for good measure!"

Conroy notes that his favorite kinds of stories "examine the outsider status of Batman."

"The challenge for me playing the complicated character of Batman is his sense of isolation and inability to connect to others," says Conroy. "Especially in playing him in the team setting of the Justice League, there's a real contradiction there.”

Green Lantern actor Phil LaMarr says the fan campaign is validating as a performer, noting, "Your first hope is that someone will see your work, your second is that it will, in some way, endure."

LaMarr says he's not totally surprised a reunion has not yet materialized, though.

"Executives tend to look for the biggest, shiniest new thing, not the best, most-loved old thing — until someone proves there’s an audience for it," says LaMarr.

But in an era where revival of old shows has become common in Hollywood, it might make sense for a return.

"There are so many fans that grew up on Justice League on Cartoon Network that seem to want to reboot some sort of movie or limited series," says Superman actor George Newbern.

Michael Rosenbaum , who voiced The Flash, says he's happy (but not surprised) fans would like to see a reunion movie, given the quality of the series' animation, direction and score.

"Why it was prematurely cancelled always baffled me. I’d be honored and grateful to be a part of any sort of reunion with all the beautiful people associated with this show," he says.

Warner Bros. Home Entertainment declined to comment.