[quotemsg=20214290,0,582021][quotemsg=20214070,0,1282023]No, not even for a free service.
OK....only if there is a specific, large, popup that tells you it is doing this, and the possible implications.
Not buried on screen 42 of a 128 page ToS.[/quotemsg]
A large popup would be "annoying and intrusive" though. The idea here is to not bother the site's users, while still profiting from their visit. I would probably rather encounter something like that than a big, autoplaying video ad that pops up on every page, using system resource for something annoying that gets in the way. So long as the script were light on resource use, it might not be bad. I would want to see at least a small logo on the page indicating that such software was being used though. Maybe there could be a play/pause button at the top of the page to allow a user to pause the mining script if desired.
The alternative is to use ads to pay for free site services, but if the majority of a site's target audience is using ad-blocking software, then they need to look for some other means to stay in business.[/quotemsg]
Going to a website and using a service does not give them free license to use your PC for "whatever", without notification.
Behind the scenes mining, a torrent node, free WiFi for the neighborhood...
If you tell me about it and I agree, maybe.
But just doing it behind the scenes? No.
And for a service I am already paying for? Not a chance.