Surf around the Web long enough, and you're going to run into CAPTCHA checkpoints.

You may be buying concert tickets or posting on a message board when -- bam! -- up comes a box of squiggly text that you have to retype before you can keep going. That's a CAPTCHA. The challenge-response mechanism is put in place to make sure that the person on the site is a human being and not just some bot bent on hoarding away concert tickets for a scalper, or spamming a forum with shady ads for erectile-dysfunction drugs.

The major player in this arena is reCAPTCHA, and now it belongs to Google (NASDAQ:GOOG). The search-engine giant is acquiring the company that protects 100,000 different sites for undisclosed terms.

Isn't that cute? The "do no evil" company is hooking up with a company that makes the computing experience safer.

Now, before you hand Google the Good Samaritan award, realize that there are commercial implications.

For starters, reCAPTCHA is in the process of digitizing older editions of the namesake newspaper at New York Times (NYSE:NYT). When you make a living protecting sites by way of tricky scripts, you grow to excel at optical character recognition, and the real prize with reCAPTCHA is its ability to convert problematic scanned images into text. This feature will come in handy, given Google's quest to keep scanning books and periodicals.

"Having the text version of documents is important, because plain text can be searched, easily rendered on mobile devices, and displayed to visually impaired users," Google explains in its blog detailing the purchase. "So we'll be applying the technology within Google not only to increase fraud and spam protection for Google products but also to improve our books and newspaper scanning process."

Of course, plain text can be more than searched, easily rendered, and displayed. In Google's world, text provides context -- and context provides the ability to slap on moneymaking ads.

Microsoft (NASDAQ:MSFT) and Yahoo! (NASDAQ:YHOO) can't be happy. Google will find ways to plaster its ads across searchable text. It will also have its foot in the door for the 100,000 customers already incorporating reCAPTCHA's verification platform.

Well played, Google. We don't need to scan this deal to know what's really going on.