Good grief of course people are mocking Islam, if Islam leads to this kind of stupidity. They are pretty well mocking themselves. Bit of a shame they need to kill people to do it.
(Incidentally, did you know that Depictions of Muhammad are
only mostly [*] forbidden (in those versions of Islam which do forbid it) because the “key concern is that the use of images can encourage idolatry”. Which means images that take the piss are fine).
[*] Updated: apologies for the inaccurate paraphrase of my source.