This is all very true. Something happens to many people when they get behind a computer*. Some people get addicted to some part of the Internet, spending hours and hours and hours on it to the detriment of the rest of their life. Many people have lost their job and family as a result.
Unfortunately, sometimes otherwise good people turn bad at the computer. These are people who would never think of stealing a candy bar or stepping on an ant or hurting anyone in person. But at a computer -- probably because of the anonymity and their high technical skills -- their personality changes; and not for good.
This is nothing new -- even back in time-sharing days using clunky teletypes there were those who would steal accounts, attempt to hack where they weren't allowed, etc.
_Someone_ is writing all those virus programs, writing sophisticated code to generate spam and bypass filters, and send out all sorts of very nasty material.
Then of course traditional criminals use the Internet as a new tool, using it as an electronic crowbar or lockpick set to break into places.
Law enforcement is after these people, of course, as they should be. But there is concern, with the anonymity of the Internet, that the identity of the criminal may be masked and given to an innocent person. I cannot change my DNA or fingerprint. But a human created every and all password and ecryption schemes and that means another human has the means to bypass or modify it.
*It's like automobiles, something happens to people when they get behind the wheel. The most sweet gentle people can turn into monsters when they drive (and vice versa).