It depends on your definition of “secure.” The links in the invites expire after a few visits, so that people can listen from both their home and office, but not widely share the link around. But a stream is a stream, and if music is coming out of a computer’s speakers, any 8-year-old can capture that music with Soundflower and have it up on MegaUpload RapidShare before their bus gets home. If that doesn’t sit well with you, we recommend you keep your music off the internet until its release date, period. If, however, your goal is to let press people stream some tracks from your new album while restricting the general public’s access, and you’re at peace with the risks that entails, then private streaming is for you.