Data Leak

I had a phishing email arrive in my INBOX today. This wouldn't be noteworthy except it was an attempt was mailed to one of my many aliases. I create these aliases so I can track who's being liberal with my data even though I always tick the "Do not share my email" boxes and generally grace the privacy policy with a quick scan. I'm pretty certain it's not a lucky guess because the mail does claim to be from that site and even uses my site user name (although the headers reveal a dubious ancestry). Considering the site in question is a certain high profile social networking site you'd think they would want to know when their database has been compromised. However despite many attempts to report it through their (shudder) web-based email form all I get is an 200 error telling me to come back later. I wonder if it's worth reporting to someone else?