Trademark attorney Michael G. Atkins of Seattle said legal parodies of commercial trademarks are protected under the First Amendment, but such religious products generally don't fall into that category.
"You could take Microsoft and change their logo around to make fun of Microsoft, and that would be legal," he said. "But I can't use the Microsoft logo to promote my Christian theme because there's no real connection there. That's illegal."
Christian themed merchandise is a $4.6 billion dollar industry and a growing percentage of the market are variations of familiar logos and commercial themes. Everything from "Got Milk?", "Rock Band", Lost, American Idol to the Subway logo have been perverted, but though it is often an obvious infringement, a lot of companies will withhold action because they don't want to appear anti-Christian.