The next frontier in the war between cyclists and drivers

A pair of vigilante cyclists have taken to placing bright green 'I parked in a bike lane' stickers on the cars of drivers and then shaming them with the evidence on social media.

After launching the idea last week with the #IParkedInABikeLane hashtag campaign, the pair's exploits seem to have divided opinion in their home city of Toronto, Canada.

They post photographic evidence on an Instagram account and are now selling the stickers via their website, which they hope will help to spread the message and prevent cars from parking inconsiderately in future. In a week, they have sold 2,500 stickers around the world, with people from as far afield as Germany, the UK, Australia and Singapore buying them.

The group's founder, who wishes to remain anonymous told i100: "Since last week I've gotten several hundred emails from people worldwide raving about the idea and asking for stickers."

"I feel like the response proves the need. It's not just us and our friends - this is a public issue that needs to be addressed."

When I ride on the road and take the lane (as I'm legally allowed to do) I get honked at, harassed, passed dangerously close, or told to get off the road and ride on the sidewalk.

• The group's founder, speaking to i100

Some cyclists have heralded their actions, others have called it vandalism and others fear it will only worsen on-road relationships between cyclists and drivers.

The group's founder explained: "The purpose isn't to damage or vandalise. It's to make drivers aware that they are breaking the law and putting cyclists in danger.

"Drivers don't realize how dangerous it is to merge into traffic, especially for cyclists who are not super comfortable on the road."

"Maybe when they are peeling the (not permanent adhesive) sticker from their car, they will take a moment to consider why this has happened, and change their actions accordingly," they added.

More: How bike schemes measure up across the world

More: This man is cycling 500 miles to meet the person who saved his life