Elon Musk has struck a deal to buy Twitter with a promise to reduce censorship on the platform, raising questions about what his approach will mean for the "digital town square".
Human rights groups have raised concerns that a lack of moderation could lead to a rise in hate speech.
Many Twitter users are also asking whether this means accounts suspended by the company will be allowed back.
The most high-profile person to have been suspended was Donald Trump.
After the news of the deal was announced, human rights groups raised concerns about hate speech on Twitter and the power it would give Mr Musk, who is a self-described "free speech absolutist".
He has been vocal in his criticism of the platform's policies on moderating content, arguing that Twitter needs to be a genuine forum for free speech.
In a statement after striking the deal he described free speech as "the bedrock of a functioning democracy".
In a Twitter thread, Amnesty International said: "We are concerned with any steps that Twitter might take to erode enforcement of the policies and mechanisms designed to protect users.
"The last thing we need is a Twitter that wilfully turns a blind eye to violent and abusive speech against users, particularly those most disproportionately impacted, including women, non-binary persons, and others."
Twitter did not immediately respond to a BBC request for comment on the concerns raised. (BBC)