ADT is suing Amazon subsidiary Ring, claiming in its filing that Ring’s recent siren designs are a “brazen” copy of ADT’s octagonal blue logo.

ADT lists a dozen of its trademark registrations dating back to the late 90s that feature a combination of blue octagonal designs, and claims millions of its customers display this symbol to show that their homes use ADT’s security systems.

ADT claims Ring’s use of blue octagons risks confusing customers and misleading them into thinking the companies are affiliated or associated. In its filing, ADT says “the striking similarity” is evidence Ring is trying “to reap the benefit of the goodwill associated with ADT’s brand and reputation.” It claimed “this type of confusion seriously undermines the goodwill that ADT has cultivated in its Famous Blue Octagon and irreparably harms ADT”.

ADT is asking the federal judge in Florida to order Ring to stop using the allegedly similar symbols and to pay ADT cash compensation. When contacted for comment, a spokesperson from ADT said the company “is determined to protect its customers, its employees, and its investors, along with its intellectual property and its reputation.”

ADT recently received a $US450 million investment from Google, which until recently sold a home security system under its own Nest sub-brand. Google said it hopes Nest devices will become the cornerstone of ADT’s smart home offering.