Facebook is reversing its January ban on cryptocurrency ads, though advertisers will have to be pre-approved and ads related to initial coin offerings or binary options are still be prohibited, the company announced in a blog post.

Facebook's original ban was intentionally broad at a time when cryptocurrencies like bitcoin were booming, and the largely unregulated space was spawning . (Bitcoin recently fell below $6,000, down from a high of nearly $20,000 in December 2017.) Following Facebook's lead, Google, Twitter, and Snapchat all instituted similar bans earlier this year.

Facebook's first policy, aimed at all "financial products and services frequently associated with misleading or deceptive promotional practices," stopped even legitimate businesses from buying advertisements. Now, however, interested advertisers can fill out an application that includes information on licensing and whether their currency is publicly traded to help Facebook determine their eligibility.

"Given these restrictions, not everyone who wants to advertise will be able to do so," Facebook product manager Rob Leathern writes in the company's blog post. "But we’ll listen to feedback, look at how well this policy works and continue to study this technology so that, if necessary, we can revise it over time."

In May, Facebook formed a new experimental blockchain group, led by former Messenger executive David Marcus, to focus on the technology that powers cryptocurrencies like bitcoin.

Facebook's widespread ban is being lifted just as Google's has begun: The search giant announced in March that its own crackdown on cryptocurrency-related ads would begin in June.