An algorithm developed by Google has the ability to decipher CAPTCHAs with 99% accuracy. The algorithm was created to read street numbers in Google Maps’ Street View and correlate them to existing addresses. Apparently this algorithm is so good at reading fuzzy numbers that Google says it can be used to read and decrypt CAPTCHA puzzles.

“We found that it can decipher the hardest distorted text puzzles from reCAPTCHA with over 99% accuracy,” wrote Vinay Shet, product manager at Google, on the company’s blog. “This shows that the act of typing in the answer to a distorted image should not be the only factor when it comes to determining a human versus a machine.”

reCAPTCHA is Google’s CAPTCHA service that protects websites from spam and abuse.

(Related: No word yet on if the algorithm could crack this inkblot-based security system)

Being able to break CAPTCHAs and reCAPTCHAs can put websites in danger, but Google says this algorithm doesn’t break the CAPTCHA system.

“It’s important to note that simply identifying the text in CAPTCHA puzzles correctly doesn’t mean that reCAPTCHA itself is broken or ineffective. On the contrary, these findings have helped us build additional safeguards against bad actors in reCAPTCHA,” Shet wrote.

More information about this algorithm can be found in a joint paper written by Google’s Street View and reCAPTCHA teams, available here.