If your mortgage is held in a securitized trust (the Plaintiff is a trustee) you should search the Securities & Exchange Commission website using their EDGAR database. The lastest discovery in foreclosure defense is that the trust may no longer exist! If the trust does not exist, the bank cannot be a trustee.
To find out if your mortgage trust has been dissolved, find the name of your trust in the database and then click on the links to the documents that have been filed. If the trust has filed a form 15-15D there is a good possibility it no longer exists because this form is used to suspend financial reporting requirements. You will need to submit an inquiry to the SEC to determine if the trust still exists because there are other reasons for filing the form, but it is definitely worth the trouble if you can get the foreclose dismissed because the Plaintiff Bank lacks standing and capacity.