Google Warning: Stop Undermining Mobile UX with Sneaky Redirects
Google warns site owners that they had better be using mobile-only redirects for the purpose of improving user experience and not to misguide users.
In other words, some sites are redirecting mobile users to unrelated content. This may occur when a searcher clicks on a link from the SERPs and they are taken to different content if accessing the link from a mobile device. This is bad UX and is against Google’s webmaster guidelines.
You can read more about sneaky redirects here.
We can assume from this that Google must be seeing a significant number of black hat redirects and is reacting to it.
Google warns that they can take action on sites that are knowingly utilizing sneaky redirects, including removal from the index.
It is possible that some sites may be triggering sneaky redirects without the webmasters being aware. This would be due to a site being hacked or unscrupulous ad programs.
In these instances, Google offers three recommendations for detection:
Test your site on mobile devices regularly
Stay aware of mobile UX and listen for feedback from mobile users
Monitor mobile user behavior via analytics
Read the announcement.