WebSockets… Are they unsafe?-Collection of common programming errors

As any technology implementation, security is up to you.

PHP Sessions aren’t safe as you can imagine for example. Check out Chris Shiflett articles for explanation on those.

http://shiflett.org/articles

I recommend for these new Javascript technology some reading about Cross-Origin Resources Sharing, Cross-Document Messaging and Web Sockets for further understanding about implementations and security drawbacks.

A good point for start searching on those topics (and many others) is http://caniuse.com/.

Remember, any raw implementation is a hole in security. Security needs to be worked out always, for any feature you want to implement.