SHE has been called the “Geek Goddess” of Yahoo! and hailed as the company’s saviour, but if you go behind Marissa Mayer’s back, expect consequences.

Former Yahoo! employee Cecile Lal has found that out the hard way and is currently facing a lawsuit brought by the tech giant for allegedly sharing company secrets.

Earlier in the year, journalist and author Nicholas Carlson published a book on Ms Mayer, titled Marissa Mayer and the Fight to Save Yahoo!, charting her time as CEO and her efforts to turn around the fortunes of the flailing tech company.

Ms Mayer refused to cooperate with Carlson during the writing of the book and was even accused of “actively interfering” with his research. Staff were allegedly warned not to make comment and as a result, the author claimed he had to rely heavily on anonymous sources to help him pen it, using “hundreds of interviews with more than a hundred sources with firsthand experience of the events described.”

“Mayer is a very powerful person and Yahoo is a very powerful company in Silicon Valley,” Carlson wrote in Business Insider in February, after the book hit shelves.

“Many of my sources only agreed to speak with me on the condition that Mayer and Yahoo! never find out they did,” he wrote.

“Many of the sources who provided me documents and agreed to be interviewed by me did so at the risk of their careers inside Yahoo!, Google, and around the Internet industry.”

But lawyers for Yahoo! believe they have pinpointed the source of much of the information used in the book and say it was unlawfully provided.

The company last week filed a lawsuit against Ms Lal, a former senior director of product management, alleging a “flagrant pattern of misusing Yahoo!’s confidential information” between April and September of 2014, coinciding with the departure of Ms Lal from the company. She is accused of breach of contract and breach of the fiduciary duty of loyalty.

A copy of the lawsuit has been published by Buzzfeed and alleges Ms Lal broke a confidentiality agreement by leaking sensitive information from meetings with Ms Mayer, known within the company as FYIs. Yahoo! also alleges Ms Lal gave her personal credentials to Carlson to allow him to access a password-protected internal site filled with transcripts of question-and-answer sessions between Ms Mayer and staff.

“Lal was eager to divulge Yahoo!’s secrets, even telling Carlson in response to a specific request that ‘if you know the date of FYI exactly or other topics discussed on that day, it will help [in] finding’ the information he sought,” Bloomberg quoted Yahoo! lawyers as saying.

Yahoo! is claiming the sensitive information has been used by its competitors to gain an advantage. If the company can prove that the information in the book led to loss in market share, a judge could potentially rule Ms Lal financially liable for lost income.

“Lal’s breach of trust and confidentiality also destabilised the trust on which Yahoo! relies in providing its employees with the greatest level of information Yahoo! has ever shared with its workforce,” the company said.

‘A CYBORG, TONE-DEAF WORKAHOLIC’

The book received some positive reviews when it was released but it’s unlikely Ms Mayer shared the sentiment.

“She was a pompom girl and a debater,” Carlson wrote of Ms Mayer’s high school days, saying she had gone on to become a tenacious and sometimes effective leader but calling her managerial style “dictatorial”.

A New York Times reviewsaid Ms Mayer emerged from the book “less as a Geek Goddess, or even a computer science nerd made good, than as a kind of cyborg, a tone-deaf workaholic who has trouble making eye contact and requires only four hours of sleep a night.”

Ms Mayer caused a minor sensation when she left Google to take the reigns at Yahoo! in 2012. Pregnant and aged 37, she was the youngest woman to run Fortune 500 company and bore the weight of great expectations. According to Carlson, she arrived for her first day of work to find posters of her face in the style of Barack Obama’s famous Shepard Fairey illustration with the word “hope” written under her face.

Yahoo! has had a tumultuous past and has been seen as a serial underachiever since exploding in value from 1997 to 1998. Some of its biggest missteps have become folklore in the tech world. In 1997 the company had the chance to buy Google for US $1 million but passed on the deal. Years later, it could have acquired Facebook for US $1 billion, a price tag Yahoo! believed was $150 million too expensive. Facebook is now valued at more than US $200 billion.

These are mistakes Ms Mayer appears keen to avoid, moving quickly to approve acquisitions including Tumblr for $US1.1 billion. But she has been criticised for the lack of value they have added to the company.

As for the defendant of the lawsuit, Ms Lal has kept out of the spotlight, declining offers to speak to the media since the complaint was filed.

Carlson on the other hand has taken to Twitter to ask for help to find himself a good lawyer.