ADT is a long-time home security firm dating back to the late 19th century, specializing in alarm and smart home security services.  Ring, founded in 2013, also manufactures smart home products, including a video doorbell product.  In March of 2021, ADT sued its rival Ring in a Florida district court for violating its trademarks by using certain signage (shown below), which ADT alleges is confusingly to the blue octagon logo that ADT has used for several decades:

ADT continues to allege that “Ring’s unauthorized use of ADT’s Famous Blue Octagon will cause confusion with ADT’s customers, potential customers and the public at large, and will cause them to mistakenly believe that there is an affiliation or association between Ring and ADT.”