When the time comes, Football Federation Australia has no alternative but to deduct competition points and heavily fine the Wanderers for this latest episode of juvenile behaviour from their fans.

The detailed banner depicting Sydney FC coach Graham Arnold engaging in oral sex – sorry, there's no delicate way of putting it – in the final minutes of an enthralling Sydney derby at ANZ Stadium on Saturday night must be the final straw for the club and the code's governing body.

FFA chief executive David Gallop is putting out many spot fires around the A-League at the moment, but reining in the perennial offenders from the RBB must be a priority.

The game is nothing without its fans but when the fans start believing they are bigger than their club, bigger than the game, it's time to deliver a blunt message about knowing their place.

"We find it ironic that it takes the FFA barely 24 hours to respond to a banner deemed 'offensive', but take over 12 months to even commence an appeals process agreed upon in December 2015," the RBB said in a Facebook statement on Monday night.

"Clearly football in this country is in the wrong hands. Football belongs to the people, not a dictatorial body or the likes of so-called expert commentators. The sport doesn't belong to the FFA, nor does it belong to the likes of Robbie Slater. F--- off with your pandering to mainstream media."

They are referring to a Fox Sports column written by Slater on Monday condemning the banner. Slater is Arnold's best mate. He's taken it personally, as anyone would when their good mate has been depicted in that way.

Was the banner homophobic? This column's first reaction was that it wasn't, although I know of some gay people at the match – some of them Wanderers fans – who immediately felt this way. The RBB has previous form with anti-gay banners at matches involving Sydney FC.

Then there's the father who tells you about his young son turning to him to ask for an explanation of what the banner meant.

Homophobic. Lewd. Sexually explicit. Juvenile. Label it however you want … it was simply out of line. It's the type of humour you'd expect on the back of a toilet door. The type of humour you'd expect from a giggling schoolkid doodling in the back of an exercise book and showing it to his mates during class.

The RBB, like other active supporter groups, has been granted special permission to enter grounds early to hang their banners and signs. Then they abuse the privilege with a "TIFO" that is crude and out of line.

Given the level of detail in this particular banner, it's clear some people have too much time on their hands. Maybe they should channel this artistic expression in some other form, perhaps arts and crafts. If they're so interested with phallic imagery, maybe a nude drawing class?

The Wanderers have until noon on Thursday to respond to a "show cause" notice issued on Tuesday. The FFA needs to hit them hard.

A fine won't do. The club's part-owner and chairman, Paul Lederer, has an estimated net worth of more than $625 million. A hundred grand will feel like ashtray change to him.

Just over a year ago, the Wanderers were slugged $50,000 and had a suspended three-point penalty placed over their heads after 19 flares were let off simultaneously at a match.

The penalty was suspended because of the club's vow to police the hooligans within the RBB. It was "the last straw". "Strong commitments" were made. The FFA copped it in the neck from some for not taking a harder line.

Fairfax Media's Mike Cockerill wanted points taken away. He wrote: "Not because it's necessarily fair, but because it could have been a means to a very important end. To fray, maybe even break, the connection between the hooligan fringe, and the game.

"They've blown the opportunity of a lifetime. Here's the thing. If you stuff a marine flare down the legs of your jeans, or a railway detonator under your coat, and you go to the football, well you're not really going for the football are you?"

The great shame of it is that the Wanderers supporters were initially something to be celebrated. Their growing presence in the club's tearaway debut season, as they filled the streets and stands in increasing numbers, represented everything that is good about football.

Some were unfairly targeted in NSW Police "shame files" a couple of years ago, and, worse still, they did not have a right of appeal over their exclusion.

That was wrong – but it doesn't make this latest behaviour right.

And we may as well counter all the cliched arguments right now.

Yes, the behaviour of the RBB is nothing compared to how other groups of active fans around the world behave, from Italy to South America. But we're not the rest of the world.

Yes, other sports have their own hooligan elements. Do the media and law enforcement agencies turn a blind eye to this behaviour? No, just ask the Bulldogs. Idiots are idiots, and they support all sports.

Yes, other fans from other A-League teams also have a lot to answer for. To that end, members of The Cove – Sydney FC's supporter group – are best advised to keep silent on this one.

They don't have to get off their high horse as much as the dozens of seats they stood on and broke at ANZ Stadium on Saturday night, before hurling them and other projectiles onto the field as it became clear that their first defeat of the season was coming.

I've been lucky enough to watch football at some of the great sporting cathedrals around the world.

Manchester United at Old Trafford. Arsenal at Emirates. Barcelona at Camp Nou. Brazil at the Maracana. River Plate at Monumental. Urunga Raiders at the bottom oval of the Urunga Recreation Reserve.

Each stadium had electric atmospheres, not completely without incident. There's the story of the elderly River fan throwing his false teeth at the referee, even though it seemed too good to be true. There were a few flares here and there, too.

But at no stage did the match require a banner depicting the coach of the rival side performing oral sex. The fans seemed to have better things to do.

Like watching the game.

Follow Andrew Webster on Facebook.