I like the idea. I think it would be nice to also include sites that store passwords in plain text. I always email sites if they send me my password in plain text. Half the time they reply and say it's not really so bad. Half the time they reply and clearly don't understand why I would even care. I've yet to see anyone admit that it's a problem. If we get could get that solved, that would really be nice.
I do this too. The typical response is that they are forwarding my concern to their technical department, and I hear nothing further, and the issue never gets resolved.