Twitter has had a-busy-year quashing some annoying-bugs. From dropping notifications every-time someone unfollowed a user to mislabelled retweets, Twitter users have seen it all. But as the year comes to an end, social-networking-giant may have one more issue to deal with. A security researcher claims he was able to match 17 million phone-numbers to actual Twitter-accounts, exposing a flaw in Twitter's Android mobile app.