Prakash said that he decided to publicly disclose the vulnerability a few days after sending his PoC script to Facebook, because the company didn't respond. Prakash even published 850 partially obfuscated phone numbers and associated names which, he claimed, represented a very small portion of the data he obtained during his tests.

"It's been about a week since I started running it and I still haven't been blocked," Prakash said Monday via email. "I even informed them [Facebook] today morning (Indian time) still no reply."

Facebook did not return a request for comment sent Monday.

Following Prakash's public disclosure, Tyler Borland, a security researcher with network security vendor Alert Logic, created an even more efficient script that can run up to ten Facebook phone search processes at the same time. Borland's script is called "" and can search for phone numbers from a user-specified range.

"With default settings I was able to verify data for 1 phone number every second," Borland said via email on Monday. "They [Facebook] do not employ any kind of rate limiting or I haven't hit that limit yet. Again, I sent hundreds of requests within short intervals of time and nothing happened."