Yes, Whisper doesn't ask for names, phone numbers or addresses, but even when you OPT OUT of having your location remembered, it still saves everyone's location.
British newspaper The Guardian discovered this past Thursday, during a visit to the Whisper office for a possible co-operation.
Whisper, in reply, calls it a lie but still changed their privacy terms with a clear warning that after a while others might recognize your identity based on your location and messages. They also say that they need to know locations to test the plausibility of the secrets. For example: if there is a secret about someone being raped at a military base, it looks more truthful when the secret COMES from a military base. The company also warns the police about dangerous secrets.
The Guardian has also found that data, believed by users to be deleted, is collated in a searchable database.
<a href="http://www.theguardian.com/world/2014/oct/16/-sp-revealed-whisper-app-tracking-users">Much more information at the Guardian source</a>
Who really believes in anonymity anymore though