It is utterly baffling to me that any US sperm bank is not properly educating prospective donors and parents about the myth of anonymity.  With DNA testing, Google and social media, anonymity is a thing of the past. Sperm banks need to stop the fallacy of selling "anonymous" donors.  Donor conceived people have been locating their donors via DNA testing since 2005 (see New Scientist Magazine 11/3/2005)- so this is not news.
The editor-in-chief of the journal Human Reproduction finally admitted to this long known fact this year: "Due to genetic testing donor anonymity does no longer exist
Many thousands of people worldwide have been conceived with donor gametes but not all parents tell their children of their origin. Genetic testing will make this impossible. Over three million people have already used direct-to-consumer genetic testing. The rapidly increasing availability of cheaper and more detailed tests poses numerous challenges to the current practice of sperm and egg donation: 1. Whether they are donating in a country that practices anonymous donation or not, donors should be informed that their anonymity is no longer guaranteed, as they may be traced if their DNA, or that of a relative, is added to a database. 2. Donor-conceived adults who have not been informed of their status may find out that they are donor-conceived. 3. Parents using donor conception need to be fully informed that their children’s DNA will identify that they are not the biological parents and they should be encouraged to disclose the use of donor gametes to their children. All parties concerned must be aware that, in 2016, donor anonymity has ceased to exist."

JLH (Hans) Evers, Editor-in-Chief Human Reproduction