Reps for Heard, who maintains 5.3 million followers on her active Instagram account, did not immediately respond to Yahoo Entertainment's request for comment. Neither did Twitter, which Heard's ex, Elon Musk, began taking over Oct. 28 in a $44 billion deal.

More than a few celebrities have said that they are taking a break from or leaving the platform altogether in the wake of its new ownership. Musk has said that he wants to promote free speech on the platform and consider the reinstatement of accounts that the company previously banned, because, for example, they were spreading false information or inciting violence.

Musk and Heard were romantically linked just after her 2016 split with actor Johnny Depp, and they went public the following year. After a short breakup in late 2017, they ended their romance for good in Feb. 2018. But they appeared to remain friendly, and her legal team even listed Musk as a potential witness in her ongoing legal battle over defamation with Depp. Musk didn't end up testifying.

Someone who did testify, though, was Christian Carino, a former talent agent of both Heard and Depp, who presented texts exchanged with Heard after her relationship with Musk ended in 2017. In one of them, Heard had texted that she was "just filling space" with Musk after her marriage ended.

Still, in May, Musk tweeted about Depp and Heard, "I hope they both move on." He added, "At their best, they are each incredible."

On the same day that Heard's Twitter account disappeared, TMZ reported that there had been another development in Heard and Depp's long legal fight. Depp reportedly filed documents on Wednesday appealing the jury's ruling in favor of her in a single count of defamation, for which she was awarded $2 million. In the same trial, Depp was awarded $10.35 million, as the court found that Heard had defamed the Edward Scissorhands star. She has also appealed the decision.