Anyone who deals with cryptocurrencies knows that mining requires very powerful systems. So if you are thinking of pursuing a "sport" you must first invest in a very good computer system. 
Recently some websites have begun to use the resources of the user system they are visiting for mining. Some of them display a notification on the screen that explains what happens before they start, while others start using your system without saying anything.
This publication refers to the second sites, which are starting to use the resources of their visitors' systems to gain cryprobes.
Who is mining? is a web application that has a comprehensive list of all known mining websites. It also allows you to check out a mining page without telling it to the end user.
Visit it whoismining.com and type the URL of the page that you suspect uses your browser to do mining cloaking. The web application will confirm whether your suspicions are true.
The app still has endless lists of webpages with that behavior.
If you see that a page you are interested in uses your computer, you can simply stop visiting it. If you can not again without it, you can block mining from your browser with an add-on or extension.
It is worth discussing whether this practice is correct or not, especially when websites choose not to disclose what they are doing. Some users of these pages have no problem to allow their mining system to be used, but it should be up to the user to decide whether or not to do so.
