1. Some of them are passive-aggressive. flickr.com 2. Some of them will give you ideas. worldwideinterweb.com 3. Really amazing ideas... tickld.com 4. Some will make you lose faith in humanity. i.imgur.com Yes, reclaimed water, that's why. 5. Some make you feel bad for llamas. i.imgur.com 6. Some of them are really about gender equality. worldwideinterweb.com 7. Some of them had to have emphasis added. tumblr.com 8. Some are mysterious. Flickr: passiveaggressive What circumstances? What was happening? 9. Some make a lot of sense. tumblr.com BIG SNOWGLOBE, your reign of terror is over. 10. Some most definitely have a painful history. i.imgur.com 11. Again, humanity... i.imgur.com 12. Some really do seem like they'd be obvious. hugelolcdn.com 13. Some give you nearly all the information you need. Flickr: passiveaggressive If I were Liz, I'd be very annoyed by my un-highlighted name. 14. Some are likely to have come from a complaint. tumblr.com 15. Some have stories you don't really want to know. i.imgur.com 16. Some you can be quite glad have been made clear. i.imgur.com 17. Again, you'd hope some would be obvious. mountainproject.com This happened enough to need a sign? 18. Others, admittedly, seem to be much rarer. images.travelpod.com Is this related to the last one? 19. Some suggest the decline of all decency. i.imgur.com 20. Some you really hope had a positive ending. i.imgur.com 21. Some have some great irony built in. i.imgur.com 22. Some might be pranks. tumblr.com 23. Some should really be redundant. i.imgur.com 24. Some are just making extra sure that everything is clear. tumblr.com In fairness, the failure to dispense cupcakes would really annoy me. 25. Some are making a bold statement against a very real threat. dailyoftheday.com 26. Some might be a cunning ploy. tumblr.com Probably by the archery club. 27. Some are spectacularly elegant put-downs. i.imgur.com 28. Some may have a grounding in cartoon physics tumblr.com 29. Some make you feel sorry for the person who discovered the need for the sign. i.imgur.com 30. And some just really need answers. memeguy.com Which is the salient part? Do they not rent pigs, or do they not rent pigs?