The FDA has rejected applications for more than 1 million fruit-, candy- and dessert-flavored e-cigarettes and vaping liquids in recent years.

With e-cigarettes and flavored vapes booming in popularity, the U.S. Supreme Court on Monday will examine whether the Food and Drug Administration unlawfully blocked the marketing and sale of more than a million new sweet and candy-flavored nicotine products in recent years.

Opening arguments in a case centering on the role of flavored vapes see justices ask many questions and display differing levels of knowledge.