Security researcher Dan Melamed has found a serious Pinterest Exploit that exposed user’s information of over 70 Million accounts. The flaw allows hackers to view the email address of any user on Pinterest. The same type of security flaw in StumbleUpon would have allowed a hacker to collect over 100 million email addresses. Pinterest Security Team is very efficient and careful with privacy issues, it has already confirmed that the Pinterest. Exploit has been patched, it is sufficient to check the owner of the access token against the user whose information is being requested, in this way it is possible to prevent any abuse.
Source: https://thehackernews.com/2013/08/pinterest-exploit-exposes-user.html