A (rather nice-looking) sign created by and placed in a trash collection area by a self-appointed "trash cop" reminding everyone that today's trash collection is over. This is to let them know not to put out more trash bags until the next collection day.
Some people are vigilant about making sure the trash on the curb of their block is properly done and that doesn't necessarily have to be a bad thing. However, some people aren't content to fix the problem quietly or wait for others to handle their mistakes. They find out where trash sorting mistakes are made and decide it's their job to harass whoever they believe has made the mistake through garbage-based-sleuthing. These garbage Nazis can be so oppressive that they have actually driven people out of their apartments with their consistent badgering. What is more, many of them are proud of being such angry jerks about something as minor as trash.
I won't miss people who have so little in their lives and get off on bullying others so much that they paw through their trash looking for mistakes and who made them.