Rainbow Tables crack passwords

From Chapter 2: Botnets Overview of Craig A. Schiller’s Botnets: The Killer Web App (Syngress: 2007):

According to the Rainbowtables.net Web site, using their tables and others on the Internet “it is possible to crack almost any password under 15 characters using a mixed alphanumeric combination with symbols for LM, NTLM, PIX Firewall, MD4, and MD5.” Their market spiel says, “hackers have them and so should you.”