As forum host once stated that, as a rule of thumb, if you want to post something which you feel might offend someone, then you should refrain from posting.
The fact that millions of people proclaimed JeSuisCharlie after the events of last week should provide a good clue as how likely you are to offend someone by recycling the slogan.
I guess it goes to show just how inadequate such guidelines are.
I for one re-iterate that I am not
offended. I do think it wasn't the most appropriate thing to post.