Leeds United fined.

[Workingman]

This comes after a supporter confronted Newcastle's Eddi Howe.

That's wrong, and I wholeheartedly condemn it. However, how can any club, any sports club, hope to police such actions?

FA Rule E21.

"a club must ensure spectators conduct themselves in an orderly fashion during matches and do not use words or behave in a way that is improper, offensive, violent, threatening, abusive, indecent, insulting or provocative."

Fans act as fans will. How can any club know what any 'fan' will do at any given time?

Hit the transgressors, by all means, but let's not pretend that the clubs are in control of their behaviour or are to blame.

[TheOstrich]

Leeds have been fined £20,000 after a spectator physically and verbally abused Newcastle United manager Eddie Howe in the technical area during their Premier League match at Elland Road on May 13.
The spectator, David Derbyshire, was sentenced to three months in jail in September and handed a six-year football banning order after he confronted Howe during the game.
Leeds had a further £20,000 fine suspended until the end of next season by an independent regulatory commission.

It is a difficult one, the perp got his just desserts, but the only other method of getting the "behave" message through to a club's supporters is "collective punishment". Next match to be played behind closed doors. And that would cost Leeds rather a lot more than £20K ......

As an aside, there is an onus laid on spectators to report perps (and it does happen) so "collective punishment" could be thought of as appropriate.

If You Hear It Or See It, Report it, The Do Nothing Option Does Not Exist.

Source: Wessex Football League Anti Racist Notice as prominently displayed in my recently-acquired Laverstock & Ford programme.
And you can download a free Reporting App from the long-running and all-pervasive "Kick It Out" organisation if you're so inclined.