G'day Dan,
[top-posting isn't offensive, but it *is* annoying ...]
Cyde brings up a very very good point. What your religion may perceive as "mocking" and "offensive", my religion, or Cyde's, may not. I'm sorry but I fail to see how this is different than the Muhammed Cartoons: the argument there is "omg it's blasphemous and disrespectful to show muhammed" and here it's "omg it's blashphemous and disrespectful to make a cross spin around".
Context is king. We have an article about the cartoons incident because it's notable, and in the article it's only sensible that we'd have an image (or at least a link to an image) of the cartoons. We would not, however, be at all impressed if someone created a userbox with a drawing of Mohammed, particularly if the userbox's creator went on to make offensive statements about Muslims.
Likewise, an article about Satanism or the Cross of St Peter would probably include an upside-down cross. Indeed, if Cyde founded a religion tomorrow which featured as its major symbol a rotating crucifix, and it one day became notable ... including that image would be acceptable as a matter of course.
When writing articles, editorial concerns trump personal feelings (NPOV, yes?). When vandalising userboxen, use some fucking common sense.