U.S. Code § 8.Respect for flag
(g)The flag should never have placed upon it, nor on any part of it, nor attached to it any mark, insignia, letter, word, figure, design, picture, or drawing of any nature.
Just like clothing with a Stars & Stripes pattern, they weren't made from actual Flags.
So a Stars & Stripes bikini is not a felony, as I heard someone say once. (Of course I guess that depends on who's wearing it...)