With the popularization of Internet， cyber crimes have become a serious problem facing us. Nowadays cyber criminals seem to be everywhere on the Internet. To illustrate， some commit fraud or lift intellectual property， others snatch passwords or disrupt e-commerce， and still others unleash viruses to crash computers. As a result， these crimes destroy network security greatly and make computer users suffer great losses.

However， we shouldn’t tolerate these cyber criminals any more. It’s high time for us to take effective measures to fight against cyber crimes. First， we should reinforce the cyber laws to punish cyber criminals strictly. Moreover， we should develop high techniques as soon as possible to improve intrusion detection and prevent cyber crimes. Besides， more talented people should be trained and more effective firewalls should be built up so as to make the net immune to all kinds of viruses.

As college students， we have responsibility to join the battle against cyber crimes. For one thing， we should not use others’ computers unless we get permission. For another， we should be honest to others on the Internet and not release or spread unreal information. In a word， it takes our common efforts to defeat cyber crimes.