So if I say to someone - "If I see you sitting on the bench by the city hall again tomorrow you might just end up with a bullet in the head." Then I add- "this isn't a threat I'm just warning you what happen if you don't listen to me."
http://artsbeat.blogs.nytimes.com/2010/04/21/muslim-group-says-it-is-warning-not-threatening-south-park-creators/
Muslim Group Says It Is Warning, Not Threatening, 'South Park' Creators
The group, Revolution Muslim, published its post after a "South Park" episode last week that depicted the founders of various religions, including Moses, Jesus and Buddha, but declined to show the Prophet Muhammad outright and instead represented him as wearing a bear costume.
The post, written by Abu Talhah Al-Amrikee, said that the episode "outright insulted" the Prophet, adding:
We have to warn Matt and Trey that what they are doing is stupid and they will probably wind up like Theo Van Gogh for airing this show. This is not a threat, but a warning of the reality of what will likely happen to them.
I guess by saying someone else will kill you - it is not exactly a threat but if they stone or parker did end up dead - this group is setting themelves up as prime suspects.