#fuckms is in use over on Twitter, as well. There it seems a bit more nuanced, as it's sometimes used to express the same kind of defiance ... but at other times used to capture frustration, sadness, and general woe about living with the disease. Similarly rich conversations under a "Fuck MS" header have taken place over on Reddit.
Of course, there are a few looking to make a buck off the #fuckms attitude and approach, with a few Etsy shops selling various wares with the hashtag. That always happens.