Stricter regulation, including large fines, is one option to force technology companies to take the issue of hate speech more seriously, the Mayor of London has said.
"We can't assume that tech companies will find the solutions by themselves," Sadiq Khan told the BBC.
He said companies have to be "chivvied and cajoled to take action".
On Monday, he will share examples of abuse he has personally received.
The messages will form part of his keynote speech at the South by Southwest (SXSW) festival in Austin, Texas.
He said the messages could deter people from entering politics or public life.