Ban the online sale of blades likely to be used as offensive weapons

In the A&E where I work I see teenagers attending with stab wounds every week. These children are not part of major organised crime but kids who take a knife to School because they think it is cool, or are scared of other kids with knives. Some of these wounds are minor and some are fatal. The most serious wounds are inflicted with long, sharp knives; popular models are the Rambo style knife and Jungle Machete. Preventing children accessing these weapons would reduce the number of deaths.