NoCoin, extension blocks sites that create Bitcoin with your PC

It’s happening more and more often that web portals ask visitors to mine cryptocurrencies instead of showing advertisements. If you want to, however, you can prevent it from happening

For some, this is the future of online monetization, a less invasive alternative to advertising. For others, however, it is a practice a bit extreme, especially when the user is not notified in time of what is happening. In short, a small case of which, probably, was not felt the need.

Complicated by the explosion of Bitcoin, Ethereum and other cryptocurrencies, many web portals are integrating, within their pages, scripts that exploit users’ computers to “mine” (generate virtual currencies in technical jargon). One example is Coinhive, a service that provides the webmaster with everything he needs (from a technical point of view) to ask his users to pay him back in Bitcoin rather than Ethereum or Monero. All the user has to do is “make available” the computer resources of his PC and wait a few seconds (usually not more than 5 or 6).

The Pirate Bay case

The one just described is the “standard” practice: not very invasive and, all in all, sufficiently clear, it allows the user to access the requested content by browsing a site with little advertising, while the webmaster is paid for his work almost immediately. It may happen, however, that some managers get carried away and, without warning, exploit the Internet users’ computer resources for the duration of their visit. This is what happened, for example, with the portal The Pirate Bay that, without communicating it to its users, started to use the processor and the video card of the visitors to generate Monero, one of the fastest growing cryptocurrencies. Webmasters justified themselves by saying that it was a simple test, but many users felt mocked.

How to block sites that create Bitcoin and other cryptocurrencies

If you want to prevent yourself from getting caught up in such a situation, you can resort to NoCoin, an extension for Chrome that allows the user to block cryptocurrency scripts from working. Free and open source, NoCoin is simple and straightforward to use. All you have to do is create a “black list” of sites and activate the extension the moment you believe that the portal you are visiting is using your PC to mine. Functioning, in short, is similar to that of adblockers, which prevent the display of online advertising.