Block anything but internet browsing through Juniper Screen OS 6.2

Hi,

We have a connection that is battered by torrents and all sorts of applications, and the session limit of 2000 on our Juniper NS5GT is quickly exceeded by the 100 devices. I tried blocking anything but HTTP and HTTPS, but I suppose that was a little bit too restrictive, as there as that stopped all internet access. What should I definitely allow in order for users to be able to use an internet browser but block anything else? Or is there a better way of achieving the same goal - reduce sessions to under 2000?

Thanks!