         let users = Keychain.getAll()
         var ret = [String : DropboxAccessToken]()
         for user in users {
-            if let accessToken = Keychain.get(user) {
-                ret[user] = DropboxAccessToken(accessToken: accessToken, uid: user)
+            if let isNumeric = user.toInt() {
+                if let accessToken = Keychain.get(user) {
+                    ret[user] = DropboxAccessToken(accessToken: accessToken, uid: user)
+                }
             }
         }
         return ret
     }
-    
+
     /// Check if there are any stored access tokens
     ///
     /// :returns: Whether there are stored access tokens
     public func hasStoredAccessTokens() -> Bool {
         return self.getAllAccessTokens().count != 0
     }
-    
+
     /// Retrieve the access token for a particular user
     ///
     /// :param: user

public class DropboxAccessToken : Printable {
    var accessToken: String
    var uid: String
    
    init(accessToken: String, uid: String) {
        self.accessToken = accessToken
        self.uid = uid
    }
    
    public var description : String {
        return self.accessToken
    }

    public func clearStoredAccessToken(token: DropboxAccessToken) -> Bool {
        return Keychain.delete(token.uid)
    }

    /// Delete all stored access tokens
    ///
    /// :returns: whether the operation succeeded
    public func clearStoredAccessTokens() -> Bool {
        return Keychain.clear()
    }

    /// Save an access token
    ///
    /// :param: token
