Cokinos Young, a midsize construction law firm based in Houston, sued its former marketing director Thursday, alleging she took confidential client contact information when she left the firm and has threatened to use client cell phone numbers to “make this a war.”

The law firm, which has 68 lawyers in five offices, is seeking a temporary restraining order to prevent Brittany O'Brien, the former director of client and external relations, from using contact information for clients to either solicit them or spread rumors. The firm is also seeking up to $1 million in damages.

“Unless immediately stopped, O'Brien will continue to cause irreparable harm to Cokinos Young for which there is no adequate remedy at law, including (without limitation) loss of goodwill, business reputation and client relationships,” the firm alleged in a lawsuit filed in State District Court in Harris County.

O'Brien referred comment to her attorney, Gregg Rosenberg, a partner at Rosenberg Sprovach in Houston, who said his client is “not looking to take any business away from Cokinos.”

The firm is alleging breach of contract, misappropriation of trade secrets and confidential information, and breach of fiduciary duty.

According to the petition in Cokinos Young v. O'Brien, O'Brien signed a confidentiality agreement when the firm hired her in 2016. She was given extensive access to the firm's database of prospective and current clients and had responsibility for managing the password-protected database.

She resigned July 16, and the firm alleged that since then O'Brien has contacted some clients by using their personal cell phone numbers, which she “intentionally kept,” and communicated with two competing firms that practice construction law.

“O'Brien has told Cokinos Young in writing that she has 'all of [Cokinos Young's] clients' personal cell phone [numbers] in my cell phone so if y'all want my narrative to change and want to make this a war I'll go there,'” the firm alleged in its petition.

Cokinos Young alleged that the client contact information is valuable and another firm could use it to “know exactly who to contact at a potential client, how to contact them, and their preferences, which increases the likelihood of winning that person's business.”

The firm said in its petition that O'Brien's resignation was due to her “continued request for a higher salary and benefits” and her threat to work for a competing firm. In the filing, Cokinos Young said it would have given her a raise but also wanted her to sign a noncompete agreement, which she declined to do.

“O'Brien's hard feelings regarding her departure have exploded into a concerted effort to contact Cokinos Young's clients and sow rumors about Cokinos Young and her departure,” the petition said.

According to the suit, the firm got a cease-and-desist letter from its lawyers at Ahmad, Zavitsanos, Anaipakos, Alavi & Mensing in Houston, asking O'Brien to return or destroy all confidential information. In response, the firm alleged, she asserted that she had no documents or files belonging to the firm or any of its client contact information on her cell phone and had not contacted clients.

“But O'Brien has refused to confirm these facts in a declaration, raising serious doubts as to their veracity and suggesting that she had now conveniently changed her story when confronted,” the petition said.

O'Brien's attorney, Rosenberg, said in an interview Thursday that O'Brien had client numbers in her cell phone from her time at the firm, but she has not reached out to clients since her departure. He said she left the firm because she did not want to sign a noncompete.

As to the text message that Cokinos Young alleged O'Brien sent, Rosenberg did not deny that she sent it. He said O'Brien sent the message because she believes some at the firm were badmouthing her.

“There's a lot of hurt in here,” Rosenberg said.