With children trick or treating today for Halloween, there are warnings to parents to make sure their youngsters are aware of stranger danger.
In some states in the US, registered sex offenders are required to put a sign on their front porch reading NO CANDY HERE.
Police say Halloween's a 'time of vulnerability' for children.
In one county in Texas sex offenders have to go to a counselling session on the night to keep them away from trick or treaters.
But some civil liberatarians have warned of the dangers to paedophiles of signs identifying where they live, which could make them the target of attacks.
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