According to a Guardian report, the service is tracking people who don't want to be tracked, and there are some issues around privacy which are a little alarming.
It transpires that Whisper are apparently sharing information with the US Department of Defense and is retaining user's posts in a searchable database.
The Guardian claims that four days after learning about the report, Whisper changed its terms of service, allowing the company to establish the broad location of people who have disabled the app's location feature.
According to Whisper: "Even for users who opt into geolocation services, the location information that we do store is obscured to within 500 meters of their smartphone device's actual location."
This is at odds with the temporary, anonymous selling point of the app, where users might have thought that anything they post would soon disappear into the ether
The Guardian report suggests "data, which stretches back to the app's launch in 2012, is being stored indefinitely."
Whisper's response: "Whisper may retain posted content for a brief period of time as stated in our terms of service, however, the internal database contains no personally identifiable information and is secure/access-audited, and not publicly accessible"
Hmmm. So what you thought was secret isn't. Who knew!