One of the reasons for establishing a shareholder site like GTAT-shareholders.com is to be able to reach out to shareholders more easily if a proxy count is needed.
It takes a lot of time to secure the proper lists, mail out proxy solicitations and get a response. Also of concern is that a broker may have five million shares but another three million can be sitting as "markers" in shareholder accounts. They have two options in this event.
1) Don't send everyone a proxy and hope they won't notice.
2) Send proxy material out and divide the responses on a pro-rata basis.
Having a way to independently record shareholders' holdings can help keep brokers honest.