// @match http://*/*
will only match addresses starting with http://… but not https://… for example.
Use the following to include all addresses if that’s what you really require (including local pages you may have saved on your hard-drive!)..
// @match *://*/*
Note: The method below also works at the time of writing by virtue of a potential bug or undocumented feature in TM2.12 (so could well be subject to change in future versions!!):
// @match *