Investing.com - Six months after banning all cryptocurrency related advertising, Facebook (NASDAQ:FB) is refining its policy to allow some pre-approved ads.In a statement , the company said it looked at the best way to "refine the policy" and decided to allow some ads, but ensure they are safe.The new policy went into effect June 26, and requires advertisers to submit an application, which will allow Facebook to determine their suitability. The original ban remains in place for ICOs and binary options, which in some cases have been linked to fraud.Facebook says its goal remains the same. And that's to prohibit ads that promote financial products and services associated with "misleading or deceptive promotional practices."Google (NASDAQ:GOOGL), Twitter and Mailchimp followed Facebook in imposing bans on all crypto-related ads.