"[Their] following is so huge with teenage girls and boys," Farr said in an interview Thursday. "It's almost like the Beatles. It's like a rock concert or something."
Nash Grier is known as "The King of Vine," with 9 million followers on the video-snippet site, and his younger brother Hayes has 2.8 million followers. Dallas has millions of followers on Twitter, Instagram, Vine and YouTube. Reynolds is listed in the top 20 users on Vine, with 3.4 million followers.
But it's what Nash Grier has said on video that has gotten the 16-year-old from North Carolina in hot water.
Specifically, according to The Huffington Post, a video surfaced in July of Grier screaming an anti-gay epithet in response to an HIV-testing public-service announcement. The clip was on an old Vine post that Grier later deleted, and when it was made public (by another young YouTube star), Grier apologized for it.
It may not be an isolated incident, though. The website The Daily Dot earlier this summer compiled a number of times Grier used similar anti-gay language on Twitter.
Farr categorized the incident as "a young kid saying dumb things.… He said some dumb things that really aren't consistent with his family values and his upbringing."
Grier did get some unsolicited advice from another celebrity who will be at Salt Lake Comic Con: "Torchwood" and "Arrow" star John Barrowman.
Barrowman, who is openly and proudly gay, recently posted a photo of himself with Grier and other "Fam Tour" members at another comic convention, reported the gay-news website The Backlot.
When Barrowman was informed of Grier's past statements, he had this to say: "When I took the picture with Nash Grier I had no idea that he'd made some homophobic comments, however he's standing with one of the biggest gay guys in the world, and if he doesn't change his homophobic attitudes and doesn't grow up, … then he's an ahole."
Farr said Salt Lake Comic Con aims to bring in as wide a variety of celebrities as possible and sometimes that means differing political views. This year's celebrity list ranges from Barrowman, who's a vocal proponent of gay rights, to "Hercules" star Kevin Sorbo, who's a conservative Christian.
"We've always seen Comic Con as an event that brings people together," Farr said. "Ultimately, we want to put together the most peaceful and most enjoyable show that we can."
Tickets for the "Fam Tour" event are $175 each, and include admission into Salt Lake Comic Con, as well as a group photo op, 8-by-10 photos and autographs.