Today, most children are advised by their parents and relatives about how they should not talk to strangers. Some children are naturally shy and avoid talking to any new stranger however on the other hand there are a bunch of enthusiastic kids who love to talk to new people. Parents feel apprehensive because they keep reading events in the newspapers about child kidnapping and other stories. Hence it is natural to caution your child about how they should avoid strangers.
A point of advise on this matter is even though you may warm your kid that he or she should not talk to someone they do not know, do not scare them with this thought. This will kill the conversations and the questions that your child may have. This will instill a fear in your child and he or she may then not want to interact with anyone. There are many parents who scold their child if they wave at someone they do not know on the road. This is not right. There is no harm if your child wants to wave or smile at a stranger and moreover as a parent if you are there accompanying the child, there is no harm.
Rather then scolding your child, try and make me street savvy and smart. Do not keep so many restrictions on your child that he or she gets afraid of his or her own shadow. Teach them the tricks of the trade and that is how they will themselves learn and feel instinctive about whom they should talk to and not talk to!