Extracting the SIP Credentials for Vonage
FettesPS has posted an article detailing a technique to extract the SIP credentials used with a Vonage account for use with the FRING iPhone application. Naturally, this could also be used for other SIP applications as well. Essentially the technique boils down to downloading your configuration settings via a specially crafted URL:
https://im-config.vonagenetworks.net/config?&login=USERNAME&password=PASSWORD&type=1003
Keep in mind that this definitely violates your terms of service and could result in the suspension of your Vonage account.