An anonymous reader writes "In an apparent reaction to the security vulnerabilities demonstrated by The H's associates at heise Security, the company behind WhatsApp Messenger is taking action against the developers of a library of functions for using the WhatsApp service via a PC. The developers have responded by removing the source code from the web. However, the popular texting alternative WhatsApp still has a major security problem. Attackers can compromise other users' accounts with relative ease, and send and receive messages from another user's account. Forked versions of the code are still available on Github."