A bit of material I share on the blog is hosted via Dropbox. A current student of mine mentioned that Dropbox links are blocked in China. So when he was home on break he did not have access to materials I linked to on my site. He mentioned Dropbox links have been blocked for around a year (although – his words – youtube and facebook have been blocked for years).
It is unfortunate Dropbox links are blocked in China, but I see no reason to change services because of this – since any service I could switch to would potentially share the same fate as Dropbox.