I'm so old I can remember when disseminating communist propaganda in public schools was frowned upon. Last Friday afternoon, I was sitting at my computer when I received an email from Peachjar. This is a service used by several school districts near me in the Portland area that sends home digital fliers to parents in lieu of paper fliers to advertise extracurricular activities sponsored by various groups in the community. My son's middle school uses this service, and I receive a few emails a month from them. I've used the service myself to send advertisements for recruiting events for Scouts,...