PHP's ``++session.use_trans_sid++`` automatically appends the user's session id to urls when cookies are disabled. On the face of it, this seems like a nice way to let uncookie-able users use your site anyway. In reality, it makes those users vulnerable to having their sessions hijacked by anyone who might:
* see the URL over the user's shoulder
* be sent the URL by the user
* retrieve the URL from browser history
* ...
For that reason, it's better to practice a little "tough love" with your users and force them to turn on cookies.
Since ``++session.use_trans_sid++`` is off by default, this rule raises an issue when it is explicitly enabled.