Respectfully, banning someone feels like the nuclear option, but maybe it's just me but there's a middle ground between that and sending SparkNotes. I mean, if someone joins a book club and never reads a single book, that's kind of disrespectful to everyone else who shows up ready to talk. My last group had a running joke about a guy who claimed he "skimmed" everything, but he basically just watched the movie adaptation and it got old fast.