An 18-year-old man has been jailed for life after setting fire to two wheelie bins in north Devon.
Homeless Christopher Brown only caused a few pounds damage when he set fire to the bins in Barnstaple.
But Judge Graham Cottle gave him an indeterminate sentence under new laws after hearing Brown threatened to commit more crimes if he was released.
Judge Cottle called it a "highly unusual case", but said he had to protect the public.
Brown must serve at least 18 months and show he is no serious risk to people before he is eligible for parole.
You admit candidly if you were subject to a community order you would commit a serious offence
Judge Graham Cottle
The new legislation applies to people over 18 who commit crimes which are punishable by life. This includes arson, no matter how small.
The court heard that Brown, who admitted the offence, told social workers he intended to commit very serious offences when let out.
Peter Ashman, defending, said: "My client is looking for a sentence which is as long as possible. He cannot countenance living in the community at all.
"It is a very sad picture and one can only hope that in time he may change his views."
Judge Cottle said: "This is a highly unusual case. He says he is going to do something very serious if he is released, he has been convicted of a specified offence and he is 18."
He told Brown: "You have a number of previous convictions for offences of destruction and damage to property.
"You admit candidly if you were subject to a community order you would commit a serious offence in order for a long prison sentence to be imposed."
"I have to consider the provisions in relation to dangerous offenders and whether there is a serious risk to the public from you committing further offences. You have answered that question yourself."
Juliet Lyon, director of the Prison Reform Trust: "Judges are grasping too readily at the straw of indeterminate sentences when they simply do not know what to do in a difficult case."
