So this issue is on our end. There is an exploit with both Apple and Android devices and some site that's allowing the popups in. They sneak in through the regular communication that places regular ads here. We're working on it, and for the short term, if you report the link that it takes you to, I can put a specific block so at least that link shouldn't come back.
This happens because malicious coders buying ad space from Google, Rubicon, and all manner of other providers, and writing ads that trigger those obnoxious redirects when you're on a desktop skin on a mobile device. It's why we have mobile skins. It's also not localized to us, it's a global ad issue, CNN, buzzfeed, msnbc, any site that uses these adsense type ads. We're trying to catch them as we get them
Here's an article on it if you want to read