INTERNET FRAUDSTARS , WAY OUT?

Every day, many innocent people are being defrauded of their hard earned money by a group of people known as internet rogues. How do we prevent this kind of thing in this modern computer age, where every thing is done through the internet?  A friend of mine was recently defrauded of a huge sum of money running into millions of Naira by a man who posed as calling from customer service of my friends bank. He collected all my friends details on a pretence  that her ATM card  has to be upgraded.   These hoodlum cleared my friend's money from her bank. It is very pathetic. How can cap we stop this internet scam in our country? What should be the way out?  Your suggestion will not be thrown out.