Quad bikes can be fun but they can also be dangerous, and people are being told to think carefully before buying them as Christmas presents. About 1,000 people a year are hurt in quad bike accidents, although experts say they are safe if used properly. But campaigners are worried that people are buying the bikes off the internet and from car boot sales, and are not getting the proper safety advice. There are also calls for a new law to make people wear helmets on the bikes. Last year about 12,000 were sold through bike dealers, who give people free training.