Opera is fighting back against secret attempts to mine virtual currencies on the internet.
The latest version of its browser, Opera 50, comes with a feature that blocks websites from siphoning your computer's CPU resources to mine cryptocurrencies.
Lately, thousands of websites, including The Pirate Bay, have used this tactic to generate funds. But it comes with a cost: although the mining occurs in the background, it can still hog your PC's computing power and drag down performance.
The other problem is that the mining often occurs without any warning to the visitor. As a result, many anti-virus companies are giving consumers the option to block browser-based cryptocurrency mining. Opera is joining those efforts by incorporating an anti-cryptocurrency mining feature into the browser's existing ad blocker.
"We are fans of cryptocurrencies but we simply don't accept that websites are using people's computers to mine coins without their knowledge or consent," said Krystian Kolondra, head of Desktop Browser at Opera in a statement.
Opera 50 launches as a stable release on Thursday. Going into the browser's settings and activating the built-in ad blocker will trigger the anti-cryptocurrency mining feature.
To screen out the mining, the Opera browser uses the "No Coin" filter list, an open-source project that Swiss web developer Rafeal Keramidas is continually updating. The filter list currently blocks a number of mining services, including those from Coinhive, which experts say is the largest provider of browser-based cryptocurrency mining.
The No Coin filter list can also be downloaded as a browser extension for Chrome and Firefox.