According to this article by Wade Williamson over on SecurityWeek.com, "In the same way that automation has transformed traditional industries, automation is transforming the economy of cyber attackers, and rewriting the rules of enterprise risk in the process. Automated attacks are cheap, tireless, and can target virtually any functionality that we expose to our end-users."
When it gets easier to carry out attacks, the number of attacks increases. Compare the frequency of the old Nigerian scam back when it was done through the postal service vs. after email caught on. Scammers no longer had to pay to make copies and buy stamps and then trek to the post office to send their fraudulent messages.
Automating attack processes widens the scope enormously. This article discusses what to do when you're confronted - as you almost certainly eventually will be - with an automated attack.