Many Greasemonkey scripts carelessly reach outside their wrapper.
This is notoriously called unsafeWindow.
This makes for a very convenient functioning script sometimes though…
(even I am guilty of doing it in most of my Greasemonkey scripts that use a site’s native jQuery 0.o)
Some things like Tampermonkey and Scriptish don’t like this wrapper reacharound.
With a name like unsafeWindow, maybe it’s not the best practice.
(I’ve even discovered that some of my scripts work better as fully inline embedded textNodes.)