If you've been accused of participating in a computer crime, it's important that you defend yourself. These crimes can be charged at the federal level, so you can be fined heavily and face time in prison. There are many kinds of computer crimes, and being accused of one in itself can mean a multitude of things. Some kinds of computer crimes may be charged in the same way as other felonies, like in the case of larceny or certain kinds of theft.
There are some special crimes that fall specifically under computer crimes, though. These include things like: modifying or damaging programs or data, interfering with computer access, falsifying email source information, stealing information about a party from a service provider, improperly accessing computer networks, systems, or computers, introducing viruses, and so on. You may already know about one common crime, which is called phishing. Phishing is a crime in which data is stolen; it can lead to identity theft or result in emails being bought or sold. Phishing typically results in things like credit card details or passwords being stolen for malicious intent.
Hacking is another kind of crime you're likely familiar with; this is when an individual breaks into a network or system without proper authorization. This can be done with malicious intent, like if a person wants to shut down a competitor's website or steal data from a government network.
Cybercrime typically uses a computer most of the time, but some crimes may only be started on the computer and finished elsewhere. For instance, email phishing scams start online, but the person stealing your information may complete the transaction elsewhere, like at a wire-transferring location or over the phone.
Source: FindLaw, "Computer Crime," accessed April 06, 2016