New York Attorney General heads up Facebook antitrust investigation

The investigation will focus on Facebook's dominance in the industry and the potential anticompetitive conduct stemming from that dominance.

James said even the largest social media platform in the world must "follow the law and respect consumers" and that she was "proud" to be leading a bipartisan coalition of attorney generals in investigating whether or not Facebook had "stifled competition and put users at risk".

"We will use every investigative tool at our disposal to determine whether Facebook’s actions may have endangered consumer data, reduced the quality of consumers’ choices, or increased the price of advertising," said James.

Joining the attorney general on the leadership team will be the attorney generals of Colorado, Florida, Iowa, Nebraska, North Carolina, Ohio, Tennessee, and the District of Columbia.

Earlier in the week, more than half of the US's attorney generals revealed they were readying an investigation into Alphabet's Google unit as part of an effort to examine its effect on the digital advertising marketplace and its impact on consumers.

As of 1610 BST, Facebook shares had slipped 1.95% to $187.18 each, while Alphabet shares were down 0.38% at $1,207.62 each.