Google is following Facebook’s lead by banning ads for cryptocurrencies and other “speculative financial products” across its advertising platforms. Alphabet Inc.’s Google said the new policy will become effective in June across ads bought on its search and display-advertising network, as well as its YouTube unit.

The policy also will restrict ads for nontraditional methods of wagering on the future movements of stock prices and foreign-exchange, such as binary options and financial spread-betting, Google said.

Facebook updated its ad policy to ban ads for similar financial products on Jan. 30. The rise in popularity and price of Bitcoin and other virtual currencies has led to scammers using online ads to promote fraudulent cryptocurrency schemes via online ads.

One new tool in the scammer’s arsenal is so-called crypto-jacking, or putting lines of code in websites or ads to surreptitiously harness the computing power of the web surfers who look at them. The power is used to mine cryptocurrency, a digital form of money that has no government or central-bank printing it or standing behind it.

Google said last year it removed more than 130 million ads that were used by hackers to mine for cryptocurrency. That is a very small percentage of the ads run on Google’s ad network.

The company’s director of sustainable ads, Scott Spencer, declined to comment on how much potential ad revenue the company would be turning away by enacting the new policy, saying the decision was made to prevent consumer harm.

The company has long banned ads promoting counterfeit goods or dangerous products, such as weapons or recreational drugs. Financial regulators are taking a close look at the multibillion-dollar U.S. market for raising funds in cryptocurrencies, raising questions about how these assets may be regulated in the future. The U.S. Securities and Exchange Commission warned earlier this month that cryptocurrency exchanges risk being deemed illegal because they don’t disclose how they determine what currencies can be bought and sold on their sites.

In addition to its cryptocurrency ad-policy announcement, Google said in a blog post published Wednesday that it took down more than 3.2 billion ads that violated its wider policies in 2017, such as those that attempted to send people to sites loaded with malware or phishing scams. The company said it removed 1.7 billion bad ads in 2016.

Some bad ads did get through its defenses—which comprise a combination of technology and thousands of human content reviewers—but Mr. Spencer said those that slipped through the net can be measured in the hundreds, as opposed to the billions.

Overall, Google said it removed 320,000 publishers from its ad network for violating its various publisher policies in 2017, while about 90,000 websites and 700,000 mobile apps were blacklisted.

Source: WSJ