More than 70 companies just signed a pledge to protect student data privacy -- with some notable exceptions

President Barack Obama announced that companies have signed onto a pledge to "enhance privacy for students" by providing parents, students and educators with "important protections" against data misuse. Pledge signers promise not to do things such as sell student information, target students with behavioral ads or use data for anything other than authorized educational purposes.

The pledge is backed by the Software & Information Industry Association and the Future of Privacy Forum. Companies that signed the pledge included Apple and Microsoft, as well as textbook publisher Houghton Mifflin Harcourt. Notably not on the list? Major education data players such as Amazon and Google, which both provide data, e-mail and other services to schools.