Amber being gone for more than 6 months because of, according to SM, her ankle injury. She was gone for so long, and almost all mentions of Amber have been omitted: in their show Koala, the 2010 SMTOWN Live Tour, and the 2011 f(x) calendar.
Some fans even started blaming the other members (there were rumours that Amber had gotten into a physical fight with another member - either Krystal or Sulli - and debated leaving the group as a whole, although this was never proven), and blasting SM in general, because of the whole Unperson fiasco happening on their show Koalanote See the "Unperson" entry on the main page.
And in January 2011, Amber suddenly reappeared out of the blue, as she was seen in a SHINee concert. Hope began to resurface for the fans. Both a tearjerker and a heartwarming moment.
Krystal's fainting at the Lotte Duty Free Family Show concert due to overexhaustion. You can see her put a hand to her head, then visibly become shaky, then collapse.
What makes this even sadder is people IMMEDIATELY started ragging on Luna for not showing the "appropriate" level of concern, as did her other members. Thing is... you can CLEARLY see Luna freaking out, she's just better at concealing it than the others.
Victoria's "scandal" with TVXQ's Changmin - she posted a photo on her Weibo of herself eating a traditional meal... and then fans zoomed in on a reflection in a spoon and happened to see the reflection of a man, who they believed to be Changmin. Cue backlash.
Luna being called fat, a whore (because she allegedly flirted with some male celebrities), and being told she can't sing.
Sulli was recently revealed to have been dating Choiza of Dynamic Duo. There's a 14 year age difference between them, and Sulli isn't exactly on the Korean public's good side (she was caught swearing on camera and then never apologized, and then later was criticized for not dancing the full choreography to "Rum Pum Pum Pum", instead holding her skirt and sitting still). But netizens... They really topped themselves this time. It's disgusting - hell, one netizen even called the others out, saying "All of you making sexual comments towards her are such trash;;; I can let swearing and other things pass but don't you think these comments are way too much for a kid who just turned 20 years old?"