He now works from his Pennsylvania home where he hopes to launch a shopping site where like-minded extremists can buy from one another.

"It's very similar to what black nationalism has tried to do with the buy black movement. We want to keep our money in the community," he said.

A similar philosophy is behind Hatreon. Cody Wilson, who launched the site in June, calls it "alternative infrastructure for people to leave the dominant platform in protest."

That platform is Patreon, a mainstream membership site for patrons to support "creators" such as artists and musicians.

"That's just wisdom to call it Hatreon," Wilson told CNBC. "In our philosophy, hate has a specific identity."

"There is a motivated group of people who have need of a service," he said. "I have no reservations serving the segment. They are not domestic terrorists."

Wilson, who is based in Austin, Texas, and runs a gun parts website, said he uses a "high-risk processor" for credit card payments because Pay Pal and all major processors dropped him.

Utsav Sanduja knows that risk all too well. He is chief communications officer and global affairs director of Gab, a social media network that has attracted a variety of users with extremist views.

"The reason we are creating the alternative economy is for the simple reason that we are witnessing [that] advertisers really hold users around the world hostage," he said.

And like the lesser known start-ups, Gab is creating its version of a shadow economy. When it launched last year, it was described as the Twitter for extreme-right hate groups, but it has attracted users from a wide range of the political spectrum.

"So Gab right now is working on an ICO [initial coin offering] and cryptocurrency. And we are currently looking at theorems, algorithms where user content can be monetized in terms of impressions," Sanduja said. "And then using that impressions system to essentially be monetized as a kind of currency that fuels it. And we're actually creating our own block chain currency. If PayPal's listening to this, hi PayPal, we're going to replace you PayPal, and we're going to replace you Stripe, and we're going to replace the whole system. And we're also going to replace credit cards and all the little bank transaction fees these big banks are taking."