From James A. Pearson VP, Global Communications, Shazam:

There is no "recording" bug. Shazam takes user privacy very seriously. Shazam does not save or send audio samples; only digital fingerprint summaries of the audio are sent to Shazam’s servers to identify media content in Shazam’s databases. As always, for user privacy, the original audio cannot be reconstructed from Shazam audio fingerprints.

For the Mac, the mic is left on for technical reasons explained below but no audio is processed, so the user's decision not to leverage our app's functionality is fully respected. As such, there is no privacy issue since the audio is not processed unless the user actively turns the app “ON.”If the mic wasn’t left on, it would take the app longer to both initialize the mic and then start buffering audio, and this is more likely to result in a poor user experience where users "miss out" on a song they were trying to identify.

So the mic being on is the first step recognizing content -- but only when the user has taken the second step and affirmatively turned “ON” the app. We believe that this configuration of the Mac app gives users the best experience, while continuing to respect user privacy.

Since there is no bug and no privacy issue associated with the current functionality, we do not have reasons to change the existing behavior. As with any other feature or apps, the team is always looking for ways to improve our user experience, but as stated elsewhere we do not have any reason to make changes.