Use your judgement. YMMV.
Heck, they should play that video for kids in middle and high school right along with their DARE and Sex Ed.
The YMMV refers to situations such as this: http://m.youtube.com/watch?v=7WEcpLi7kB4 Exercising your rights is never the easiest path but never, never let yourself be interrogated by the police. You are not required to allow yourself to be questioned, and there is absolutely no possible way being questioned can ever help you. Get a lawyer, the police can talk to them.