A: Assuming the card being taken away from someone is a character Keeper, the following can trigger You Can’t Take This Guy From Me (YCTTGFM): Mix It All Up, Trash Something, Steal Something, Exchange Keepers, Plunder, and Keeper powers that let you take someone else’s Keeper.
Cards which definitely DON’T trigger YCTTGFM would be things which take cards from your hand, like Use What You Take, or Random Tax.
We would agree — YCTTGFM is a bit harsher than average for Fluxx, but there it is. Fluxx cards can vary from harmless or ineffectual to… taking someone’s whole hand. It does tend to even out, on the whole, we feel.
If you really hate the card, feel free to take it out of your deck. Totally your prerogative! Fluxx is supposed to be fun, so if this takes the fun out of it for you, then ditch it. We want you to have fun!