Browsing to the Zippyshare URL currently results in a 403 Forbidden error from their nginx server for me, the connection is over HTTPS with a valid signed certificate so no sign of it being intercepted and blocked by Virgin Media, it also shows the same error via EE 4G.
I suspect it might just be an issue with their website.
Just tested it using the HMA Web Proxy ( https://www.hidemyass.com/en-gb/proxy ), it works as long as you don't choose London, UK as the server for it to load through, with that information it's most certainly something on their end. Considering it resolves to the same IP globally I'm not sure what might be causing such a specific country based issue, but it is actually managing to connect to their frontend web server it's just something in their server configuration is wrong.
Which returns a link, which is then blocked by VM. It's DEFINITELY been blocked by VM (advertently or inadvertently) - I assume on copyrights grounds, they probably just haven't let people further down the chain know. The site works perfectly well with other providers (I tried O2 and a VPN in Singapore), and the VM block is any Zippyshare address at all - not just those with zip or rar files.
It's annoying, but, their gaff, their rules. They've probably had enough cease and desist letters and thought "Sod it".