How do I learn who is participating electronically in a case?

In ECF select Utilities, then under the Miscellaneous category heading select Mailings and then Mailing Info for a Case.  Enter the case number and submit.  An Electronic Mail Notice List should appear, along with access to a list of case participants to receive non-electronic (manual) notice.  The electronic participants are also listed on an NEF that is emailed in a case after a document is filed.  The contents of an NEF may also be viewed by clicking on the "silver bullet" hyperlink next to each electronically filed numbered entry on a case docket.