Well with groping of women in clubs, it's pretty much a worldwide problem. Talk to a few of the members of the opposite sex, you'll find that of those that go to clubs, most if not all have had it happen at some stage, yet you know what is missing? Stories on men being prosecuted for doing so. Clubs admit it's an issue and kick out the repeat offenders, but they rarely get the police called on them.
In the search I did, though admittedly limited, I found 5 cases going back 7 years (most in the UK but one in the US) where a guy was prosecuted, and in all but one case he was arrested not for groping, but rather because they got violent on being challenged.
One broke a bottle of his victim's husband's head when challenged.
One punched, knocked down, and then started kicking his victim's two female friends when they intervened.
One was thrown out but returned to the club and violently attacked the bouncer trying to force his way back inside.
One started fighting with the bouncers when they tried to remove him, and then attacked the police when they arrived (this was the US one.)
The final one was charged with 3 counts because he was a known serial offender and got fined a grand total of 600 pounds.