A user-generated mobile content provider has apologised after north Somerset secondary school students seized on a YouTube-style instructional video on "how to roll the perfect joint".

Teacher George Beckley alerted nascent Swedish firm Tocmag after students were caught sharing the anonymous director's "top ten activities to try when you're caned." The clip was downloaded an estimated 5000 times during December.

The video was swiftly deleted from the service.

Tocmag founder Brad Ells said: "We unreservedly apologise for this oversight and we're doing everything in our powers to ensure it doesn't happen again. From the outset of this project, we realised illicit content is a serious problem with user-generated material. We have conducted a review of our censorship process and ramped-up the resources we devote to ensuring Tocmag is a clean service."

Mr Beckley explained the mobile 2.0 paradigm to The BBC: "It is part of a whole new wave of different media. It may start outside school but it is being brought in and things like this video are spread by word of mouth."

User-generated users? It's a new one on us. ®