US Patent 9491155 Account generation based on external credentials

Techniques are described for using a credential, such as a user identifier associated with an account on a first service, to create a reusable account on a second service. The account may be initially activated based on the receipt of a passcode sent to the account on the first service. The account may be created with access to a subset of features on the second service. On receiving a password for the account, the account may be modified to access a broader feature set. The account may be reusable via a cookie or other token placed on a user device, and reusability may be disabled on detecting possible security risk conditions associated with the user identifier.