sparking discussion or controversy (or both)

A church in New Zealand has a billboard up with Mary (the mother of Jesus, not one of the others) with a positive pregnancy test in her hand.  The church says that they're trying to "avoid the sentimental [and] trite" and to "spark thought and conversation."  They've definitely avoided sentimentality.  Of course, a billboard from two years ago with Joseph and Mary in bed was defaced, so this year's billboard seems to be faring better.