As the closest thing to a leader the Justice League has, you'd imagine that nobody on the team tries to mess with Superman. Although this is an entirely logical thought, it's also one that's entirely wrong, as it seems that the Man of Steel's incredible powers and authoritative position only encourage people to mess with him more.
And, perhaps more worryingly, it also seems to cause many League members to think he never needs any help whatsoever, leading to a whole bunch of scenarios that could have easily been sorted with about a thimble of effort on the part of heroes like Batman or Cyborg.
Naturally, this results in all sorts of terrible things happening to Clark - and, worse yet, he doesn't even seem to ever resent anyone for it, even when the League do things like let Lex Luthor join the team, which must be worse than Krptonite under the nails for the unfortunate Man of Steel.
Between brain bombs, sex tapes, and family disputes, the Justice League could probably do with a group therapy session or two, just to talk out why they sabotage their golden boy so damn much.
10. Not Explaining How His Powers Work - Superman (Vol. 3 #40)
When Superman discovers he can temporarily lose his powers after discharging a powerful solar flare, the Justice League decide to do the natural thing, and to totally mess with Clark while he's in a more vulnerable human form.
Part of this includes taking him to a bar, where he gets promptly wasted, since his weaker form has absolutely no tolerance built up against alcohol. After this, they get him some fries, and send him off to bed in his apartment. While none of this sounds dangerous, it has to be kept in mind that the Man of Steel still tries to save the day the next morning, and almost dies as a result.
Though none of the League would have wanted their night out to equal Clark's death, it's surprising that nobody thought that the hungover Superman would likely forget he'd lost his powers in the first place, as they could have prevented him from almost dying by literally letting him sleep at any of theirs, where they could keep an eye on him.
It's all done in good fun, sure, but you'd think someone would leave the Man of Steel with a pamphlet on hangovers or something - or at least keep an eye on Metropolis so a semi-powered Supes wouldn't end up in a fight he can't win.