Well, the hijacks don't appear to be completely limited to iOS devices. Got this last night on Windows 7 using IE. Note that some info (like my IP address) has been removed from this screenshot.

I loaded a couple threads in new tabs, and when I went to the first one, it had been redirected to this page.

No, my computer is not infected with anything. The warning is obviously 100% fake, but I even double checked before posting (full scans with antivirus and malwarebytes pro) to ensure that it didn't originate on my end.