GoDaddy Inc, Alphabet's Google, security firm Cloudflare and other technology companies moved this week to block hate groups after weekend violence in Charlottesville, Virginia, where white nationalists had gathered to protest removal of a statue of Confederate General Robert E. Lee from a park.

"We strongly believe that what GoDaddy, Google, and Cloudflare did here was dangerous," Cindy Cohn, executive director of Electronic Frontier Foundation, wrote in a blog post along with two other staffers.

The blog post reflected years-long tension in Silicon Valley, where many company executives want to distance themselves from extremists but are concerned that picking and choosing what is acceptable on their platforms could invite more regulation from governments.

"Protecting free speech is not something we do because we agree with all of the speech that gets protected," Electronic Frontier Foundation wrote.

"We do it because the power to decide who gets to speak and who doesn't is just too dangerous to hand to any company or any government."

The group called on companies that manage internet domain names, including Google and GoDaddy, to "draw a hard line" and not suspend or impair domain names "based on expressive content of websites or services."

The blog post echoed concerns expressed by Cloudflare chief executive Matthew Prince, who on Wednesday said he decided to drop coverage of neo-Nazi website Daily Stormer but said that his decision was conflicted.

Prince told Reuters he "wholeheartedly agreed" with the Electronic Frontier Foundation's post and said he was hopeful it would help spark a more thoughtful debate about internet regulation.

Google and GoDaddy did not immediately respond to a request for comment about the blog made outside normal business hours.

The Daily Stormer helped organize the protest in Charlottesville, at which a 32-year-old woman was killed and 19 people were injured when a vehicle drove into counter-protesters. The website cheered the woman's death.

It was removed from GoDaddy and Google Domains after they said they would not serve the website.