All fashion designers draw inspiration from the world around them and from their competitors, but fast fashion stores are frequently accused of crossing the line between being inspired by a designer and copying the item entirely. Fast-fashion brands like Zara and Forever 21 are frequently accused of crossing the line between being inspired by a designer and copying the item entirely.
Fashion does not enjoy the same level of protection as other creative media such as art, literature, and film. This is because, by nature, fashion items serve a purpose, which means they are exempt from copyright laws. There are certain ways to protect a product's design, but the process to do so is time-consuming and expensive. Retailers can use trade dress trademark laws to protect the visual characteristics of a product: the color, original pattern, or unique design element, for example, that are specific to that designer or product.
Designers can also file for a design patent, but these are expensive and can take around two years to process. Even if designers do decide to take the option to sue for copyright infringement, this lengthy process is undermined by the speed at which fast-fashion stores can have copycat items on shelves. This means that fast-fashion retailers are less intimidated to make products that are strikingly similar to what's seen on the runway.
Some retailers aren’t willing to give up without a fight. Adidas is extra aggressive at protecting trade dress and trade markets.