Police have condemned young people who use mobile phones to video through the windscreens of cars while they drive.
Internet video shows people filming while driving
Films of the craze are increasing on the video-sharing website YouTube. Fife Constabulary has warned drivers that they will be prosecuted if caught.
A film of a driver doing over 100mph on a rural road in Fife is being examined by officers. It shows the man's face and police want to trace him.
Road safety teams have described the practice as reckless.
Head of roads policing, Ch Insp Alex Duncan, told the BBC Scotland news website: "Driving is a serious responsibility and you've got to have all parts of your brain thinking about driving to make sure that you're safe and other road users are safe.
"If you're doing that [filming], you're not concentrating on the road and that, at the end of the day, is what's going to keep you safe."
Police have warned that legislation does allow them to prosecute drivers caught taking mobile phone footage when they are behind the wheel.
In 2007, 14 people were killed on the roads of Fife and officers have warned that this craze could lead to more deaths.
Much of the problem is centred around rural roads in the East Neuk which are often long and straight.
Local councillor Elizabeth Riches said: "It's very easy for them to boast about what they do and they can put their films actually onto the internet but what isn't easy is for them to imagine the burden they would have to carry for the rest of their lives if they were responsible for someone's death.
"They find it very easy to think that they can cope with their cars and that they are almost immortal."