A too-large minority of men are creepy / pervy and of that minority some will go to quite some lengths to access their targets.
Age about 12 - 20 is peak for men being weird and pervy at girls - because the pervy men know that younger girls simply do not know how to react, they are less likely to report it, they are more likely to be upset, scared etc which the pervy men like. This is well known by the vast majority of women.
The changing rooms in topshop with their flimsy curtains and girls aged 12-20 in a state of undress is therefore a pretty clear target.
Topshop have said that men are welcome. Not even transwomen - men who want to go in there.
This is very not good.
The fact that boys fall prey to sexual predators is also appalling but not the point here. I also think that the mechanisms for male predation seem to be different - although not being a man I'm not sure. I know that DH & his friends have never been wanked at by a random. I know that me and all of my friends have.
Why do we need to pretend this is not an issue, while at the same time #metoo is going on?