Summary
In this chapter we learned a small bit about some of the tools that can be used for (and were ALL designed for) beneficial means. Yet these same tools can provide critical information that can lead to a penetration of your site. Learn these tools, and also learn what they look like when being used by reading your logs and testing. Don't take the drive-by scans passively and just think you have to put up with them. Security, at the end of the day, is your responsibility.
Additionally, I feel I must add this word of caution: DO NOT attempt to locate and use these tools yourself. Be aware of them, be vigilant, but do not use them or seek them out. They are dangerous and can cause widespread problems, both on your own system and on systems you may interact with. Stay on the RIGHT side of the law.