By John Ostapkovich

CHESTER, Pa. (CBS) — The term “fan” is thought to be a shortened version of the word fanatic, but for these Philadelphia Union boosters, maybe it’s fantastic.

That’s because these fans, known as the “Sons of Ben,” are the subject of a new movie, now in production.

They’re known to be loud, sometimes rude.  And that their initials are “SOB” is no accident.

Oddly, the fan club actually preceded the founding of the Philadelphia Union franchise — not to mention the construction of the stadium in Chester — and played a role in those successes.

Sons of Ben president Matt Ansbro says members have gotten some camera time in the new movie.

“Last year the director, Jeff Bell, was following us around, doing individual interviews,” Ansbro recalls.   “He’s kept us in the loop in terms of everything that was going on.  We’ve been actively participating when we need to be, and then we’re just letting Jeff do his thing in the creative process.  So it’s been a cool experience for sure,” he tells KYW Newsradio.

The Union opens its fourth season this Saturday, and nobody will need to yell “action” to get some theatrics out of the Sons of Ben.