Matt Cutts, the head of Google's webspam team, was at at the recent Web 2.0 Expo offering some tips to help users who manage websites fight back against spam.

"Spammers are human," Cutts said. "You have the power to raise their blood pressure. Make them spend more time and effort...If spammer gets frustrated, he's more likely to look for someone easier."

Here are a few of his tips, courtesy of Cnet:

• Use captcha systems to make sure real people, not bots, are commenting on your site. He uses a simple math puzzle-what's 2 + 2?-but he also likes KittenAuth, which makes people identify kitten photos.

One blogger merely requires people to type the word "orange" into a field. "The vast majority of bots will never do that," Cutts said.

• Reconfigure software settings after you've installed it. A little modification of various settings will throw bots off the scent. "If you can off the beaten path, away from default software installations, you'll save yourself a ton of grief," he said.

• Employ systems that rank people by trust and reputation. For example, eBay shows how long a person has been a member and how satisfied others are with transactions with that person.

For more tips, check out PCMag.