Zend Framework应用程序设计——应该在模型层中访问会话变量

I am working on this app that accesses session variables in the model layer. This just seems wrong but am willing to be proven wrong. Maybe not wrong but, in most places in app, session variables are handled in controller and passed in as arguments but, in other places, the session value is just accessed. Am I wrong that this seems like bad practice?I am working on this app that accesses session