Spotify has just announced on their blog that they discovered an incident of “unauthorized access” to their systems and internal company data, but are taking immediate response. According to Oskar Stal (CTO, Spotify), the company’s investigations have shown that only one Spotify member’s user data has been accessed, and this did not include any password, financial or payment information.
However, as a general precaution certain Spotify users will be asked to re-enter their username and password to log in over the following days, and Android users will be guided to upgrade to a new version during the same period as well. Offline playlists will have be re-downloaded after the upgrade, but at the moment no action is required by iOS and Windows Phone users.
Source: Spotify blog