The U.S. Department of Justice is filing suit against HPE to block its January 2024 attempt to acquire Juniper Networks, one of the company’s rivals in the wireless networking solutions space, for $14 billion. According to the lawsuit, HPE executives for years showed “concern” about Juniper due to its fast-growing AI, called Mist, which helped the company achieve rapid growth. 

If Hewlett Packard Enterprise and Juniper combined, HPE and industry leader Cisco would control more than 70% of the national market, raising flags around antitrust, according to the DOJ’s complaint.

To back things up: Juniper acquired an independent networking startup called Mist Systems, which had been building tools for remote cloud management, AI, and machine learning, in 2019. Mist AI uses machine learning and data science to “materially decrease the cost of operating a wireless network,” according to the complaint, while also increasing “the productivity of network administrators.”

Mist kickstarted rapid growth for Juniper: The organization saw its market share increase by 6.5% in just two years after the acquisition, despite limitations brought on by the pandemic. 

HPE allegedly felt threatened. According to the lawsuit, “in 2021 and 2022, senior HPE executives shared summaries of Juniper’s quarterly earnings reports, noting that in one quarter ‘Mist double[d] revenue!’”

In March 2021, Juniper hosted a public webinar to talk about Mist’s AI capabilities, the complaint states. The company described its innovation as “new,” while calling HPE’s technology “old.” In response, a former senior VP of sales for the Americas told employees in an email to fight back against Juniper, saying that there “are no rules in street fights.”

He allegedly concluded his email saying, “KILL MIST!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!”

Intimidated by Juniper’s growth, HPE launched a “Beat Mist,” campaign with targeted marketing and price scaling. In a company-wide group chat, company executives shared tips about Mist’s hardware and software features in an effort to hopefully give HPE a leg-up. The group chat was used up until January 2024, when HPE decided to stop trying to beat Juniper and buy it instead, settling for an eight-figure price tag. 

Fortune reached out to Hewlett Packard Enterprise for comment regarding the suit and comments surrounding Juniper and Mist. The company pointed to this statement found on its website about the suit.

“We believe the Department of Justice’s analysis of this acquisition is fundamentally flawed and we are disappointed in its decision to file a suit attempting to prohibit the closing of the transaction,” it said. “We will vigorously defend against the Department of Justice’s overreaching interpretation of antitrust laws and will demonstrate how this transaction will provide customers with greater innovation and choice, positively change the dynamics in the networking market by enhancing competition, and strengthen the backbone of U.S. networking infrastructure.”

The DOJ complaint was filed in the Northern District of California and alleges the deal would demolish competition in the wireless local area network (WLAN) and lead to higher prices for consumers in violation of the Clayton Act.

“HPE and Juniper are successful companies. But rather than continue to compete as rivals in the WLAN marketplace, they seek to consolidate — increasing concentration in an already concentrated market,” said Acting Assistant Attorney General Omeed A. Assefi of the Justice Department’s Antitrust Division in a statement. “The threat this merger poses is not theoretical. Vital industries in our country — including American hospitals and small businesses — rely on wireless networks to complete their missions. This proposed merger would significantly reduce competition and weaken innovation, resulting in large segments of the American economy paying more for less from wireless technology providers.”