Trend: Upskirt photographs.

From the Guardian:

One summer day in 2006, Lucy Parkinson, then 21 years old, was shopping in Ealing, west London, when she heard behind her an altercation between two men. "I was crossing the road, and got stuck with a pack of other people at a traffic island," she says. "I was wearing a long-sleeved blouse and a white knee-length skirt." One man ran off and the other told her he had "chased him away because he had seen him 'upskirting' me".

Upskirting is the term used to describe taking photographs, often on a mobile-phone camera, up an unsuspecting woman's skirt.

"I hadn't even noticed it happening," says Parkinson, "and that's the most unsettling part - in a city, you just don't notice physical proximity to strangers. It could have happened a dozen other times too, for all I know."

It is impossible to judge how many women have been victims of upskirting, though a quick internet search yields hundreds of sites with hundreds of thousands of images. And there may be millions more pictures on phones and laptops that have never been shared. They have been taken in the street, on escalators in shopping centres, on trains, at bus stops and in supermarkets, schools, offices and nightclubs.