Facebook also appeared to have shut down some applications the Journal found to be transmitting userIDs, including several created by LOLapps Media Inc.
Craig Wills, a professor at Worcester Polytechnic Institute who has studied how social-networking sites handle userIDs, said such referral data are a growing problem for the Web.
Facebook promised that it would address the issue of developers unknowingly dishing out Facebook userIDs to third parties, and it's now finally laid out it's full response to the problem.
While some carriers still use phone numbers to identify specific user devices or accounts, Apple has abandoned them in favor of unique device IDs (UDIDs).