I think you misunderstood the exploit for identifying the anonymous comments. It works with pretty much any survey where you can individualize communications:

I create 20 accounts on your service. I put my picture on all of them. I send out a different link/profile to each one of my 20 friends and track which one went to which person.

I then compare notes to see who said what.

Note that it's also really easy to do this using a URL shortener service that keeps track of times clicked, user agents, referrers, and IP addresses:

http://➨.ws/anonymous_survey

By using the timestamps you provide for the comments, I can tell which of my friends most likely made each comment.