When white supremacists plan rallies like the one a few days ago in Charlottesville, Virginia, they often organize their events on Facebook, pay for supplies with PayPal, book their lodging with Airbnb and ride with Uber. Technology companies, for their part, have been taking pains to distance themselves from these customers.

But sometimes it takes more than automated systems or complaints from other users to identify and block those who promote hate speech or violence, so companies are finding novel ways to spot and shut down content they deem inappropriate or dangerous. People don’t tend to share their views on their Airbnb Inc. accounts, for example. But after matching user names to posts on social-media profiles, the company canceled dozens of reservations made by self-identified Nazis who were using its app to find rooms in Charlottesville, where they were heading to protest the removal of a Confederate statue.

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That doesn’t mean these companies aren’t feeling the pressure from advertisers and users who fear that pages belonging to alt-right publications like the Daily Stormer could incite violence, said Daphne Keller, Director of Intermediary Liability at Stanford Law School’s Center for Internet and Society. The Daily Stormer’s web domain support was revoked this week by GoDaddy and then Google, and Twitter suspended several associated accounts. Technology companies are likely to be evaluating their options in consultation with organizations including the Anti-Defamation League before shaping their policy, Keller said.

“What’s pushing them is probably a mix of people being revolted by the content, plus the public and advertising pressure,” said Keller, who is also former associate general counsel at Google. “Everything they’re doing is because they want to, or because of public pressure. But not because of the law.”