In-N-Out sues Smashburger over 'triple double' burger

IRVINE, Calif. -- It's a full-on battle of the burgers. In-N-Out is taking fast-food rival Smashburger to court over a stacked-patty creation.

The Irvine-based company claims Smashburger's "triple double" comes way too close to In-N-Out's "double double" burger.

In-N-Out filed a trademark infringement lawsuit Monday, saying Smashburger's latest menu addition could confuse customers.

The double double has been a staple at In-N-Out since 1963.

Denver-based Smashburger was founded in 2007 and launched the "triple double" last month.