This excerpt taken from the PRVT DEF 14A filed Nov 3, 2009.
Will my shares be voted if I do not return my proxy?
If your shares are registered directly in your name, your shares will not be voted if you do not vote over the Internet, by telephone, or return your proxy or vote by ballot at the Annual Meeting.
If your shares are held in street name, your brokerage firm, under certain circumstances, may vote your shares for you if you do not return your proxy. Brokerage firms have authority to vote customers unvoted shares on some routine matters. If you do not give a proxy to your brokerage firm to vote your shares, your brokerage firm may either vote your shares on routine matters, or leave your shares unvoted (broker non-votes). Shares represented by such broker non-votes will not be considered as present and entitled to vote with respect to the non-voted matters. However, shares represented by such broker non-votes will be counted in determining whether there is a quorum. We encourage you to provide voting instructions to your brokerage firm by giving your proxy. This ensures your shares will be voted at the Annual Meeting according to your instructions. You should receive directions from your brokerage firm about how to submit your proxy to them at the time you receive this Proxy Statement.