Grok is a free tool which users can tag directly in posts or replies under other users’ posts to ask it for a particular response.
But the feature has also allowed people to request it to edit images – and ask it to digitally strip people of most of their clothing.
Grok has fulfilled many user requests asking it to edit images of women to show them in bikinis or little clothing – something those subject to such requests have told the BBC left them feeling “humiliated” and “dehumanised“.
However as of Friday morning, Grok has told users asking it to alter images uploaded to X that “image generation and editing are currently limited to paying subscribers”.
It adds users “can subscribe to unlock these features”.
Some posts on the platform seen by BBC News suggest only those with a blue tick “verified” mark – exclusive to X’s paid subscriber tier – were able to successfully request image edits to Grok.
Dr Daisy Dixon, a lecturer in philosophy at Cardiff University and female X user who said she had seen an increase in people using Grok to undress her, welcomed the change but said it felt “like a sticking plaster”.
“Grok needs to be totally redesigned and have built-in ethical guardrails to prevent this from ever happening again,” she told the BBC.
“Elon Musk also needs to acknowledge this for what it is – yet another instance of gender-based violation.”
Charities campaigning to end violence towards women also criticised X over the move.
“To restrict access to paying subscribers is not only inadequate – it represents the monetisation of abuse,” said Emma Pickering of Refuge.
She said while limiting the feature to paid X users may reduce volume, abuse had “simply been placed behind a paywall, allowing X to profit from harm”.
Meanwhile Andrea Simon, director of the End Violence Against Women coalition, said “we are not convinced that X will take action to identify and prevent this, given it has dragged its heels with tackling this abuse”.
Prof McGlynn said X’s response echoed its approach to pornographic Taylor Swift deepfakes on the platform last year – where it blocked searches for sexualised material generated of the popstar using a Grok AI video feature.
“He is doing this to stoke free speech arguments,” she added.
“He will claim regulation is stifling people’s use of this technology. But, all the regulation requires is that he takes necessary precautions to reduce harm.”