For the life of the Internet, the art of protecting online e-mail addresses has rested upon the ability of web developers to come up with effective ways to sort man from machine.  In short, a CAPTCHA.

If a machine can identify and grab your e-mail address, you will become a target for SPAM - but removing your e-mail altogether is not an option if you want to provide legitimate clients and leads with a way to reach you without having to leave their computer.

When I first started looking at website code (back when a 28.8 baud audio modem was state of …

As I mention in, “Who is That on Your Website: Man or Machine,” a CAPTCHA is any automated process designed to differentiate between human and computerized posters.

CAPTCHA is especially useful for protecting your online forms, though it can also be helpful in keeping spammers from hijacking your blog, forum, or sign-up procedures.

Depending on your security needs, different kinds of CAPTCHA may be preferable.

Pre-built CAPTCHA

If there is a reason why someone would want to create multiple accounts on your page or frequently access some of your restricted information, you will want CAPTCHA which is harder to …

Given the choice between having a human visit your website and having a machine visit your website, you would probably prefer the human.

Humans are more likely to be responsible for purchasing choices, humans are more capable of understanding what you write and coming up with reasoned replies, and humans are more likely to generate original content of their own.

Unfortunately, since computers are themselves a form of machine, you can’t just forbid all contact from other machines or you would never have anyone visit your site.

The Turing Test

Before the first computers were ever built, Alan Turing theorized that it would eventually …

If your website has an unprotected contact form, sign-up form or guestbook, you are asking for trouble. Websites large and small, old and new, popular and rarely visited—all are at risk. You need to protect the data your clients provide!

What is the problem?
Internet robots (aka “bots”) find web forms and maliciously interfere with them. Bots can send thousands of spam emails through otherwise respectable web forms. Bots can also fill in the forms, signing up for e-mails, and even ordering the services and products you offer. Some bots use virus-laden attachments to get into forms to steal users’ passwords and …