This will definitely become a trend, and you should be prepared, unless you don't mind.
I hope by now you are aware that websites can be mining cryptocurrencies while you are browsing. This was previously reported about The Pirate Bay. I guess that doesn't surprise anyone due to the fact it is mostly used to download pirated content, and therefore it becomes a visit at your own risk website.
But now there are reports that Showtime's website has also been mining Monero through unsuspecting visitors, slowing down their CPUs. There hasn't been a response from Showtime or its parent company, CBS, that I know of yet, but I wouldn't be surprised if they blame it on a rogue developer.
In both cases, the script used is Coinhive's, which clearly mentions on their own website that you should warn your site's visitors about the running script.
Unfortunately, I believe this will continue on, and legit websites will be considering cryptocurrency-mining scripts as an alternative to ad revenue. But, let's face it, there's no guarantee they won't have BOTH script-based mining AND ads.
How can you prepare? I know for a fact that Malwarebytes blocks all Coinhive traffic, so anti-malware software is one step. For Chrome users, there are extensions that block miners (I use one called minerBlock, seems to work fine).
There is also the possibility that you actually don't mind and/or even prefer the script-based mining to the ads. But I don't believe you will feel that once your CPU's usage goes to 100% and your computer lags.
What do you think about this trend?