What have caused the rise in computer crimes and new methods of committing old computer crimes?

Many factors contribute to the rise of cybercrime, including (but not limited to):

• The increased use of computing in critical applications like Banking or Military installations, where criminals may wish to access sensitive data.
• The increased use of computing in our personal lives - as more people use online services every day, there's more possibility for individuals to become targets of cybercrime, such as identity theft or access of personal information.
• Increasingly complicated and large-scale operating systems mean attackers have more opportunities for identifying vulnerabilities and opportunities for attacks.
• People download and open files and documents more often and frequently every day, meaning attackers see greater opportunity to spread malware and viruses.