"alesj" wrote : | I guess it doesn't do any harm ... Yes it does potential harm because you can get access to classes and resources from other classes that you shouldn't be allowed to. e.g. in your example you can load unexported classes from fcl which you can't do from cl That's why you need the RuntimePermission("getClassLoader") like you do for class.getClassLoader(). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4201417#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...