And ^that^ is why you NEVER EVER let your browser run an application without asking you about it!!! Check your browser security settings - somewhere you should be able to set permissions for that...
I am using Chrome so can you tell me a good add on or can you tell me how to set that permissions. let me know. Also if they are not going to mention it I found it my self that this site is doing something strange.
I was just thinking what coin they were mining and is it profitable then putting ads on website?