Security researcher Dan Melamed discovered flaws in Pinterest and StumbleUpon that could have enabled an attacker to find users email addresses. The flaws were simple to exploit and could have been used to build a huge list of email addresses from a list of users for spam or malicious purposes. Pinterest has responded quickly to protect users’ privacy and gave Melamed permission to share his findings with the security community. However, the security researcher was unable to gain permission to reveal the exploit. The security researcher said the flaw would have allowed a hacker to collect more than 100 million email addresses in the hands of a hacker.”]