^^^^
They spread disease in the form of their waste. They feed off of human detris and release it from their cloaca - a mix between urine and crap. Let's just say that even though you hear all these reports of humans being so terrible for the environment, we've actually benefited the environment as well. Animals who can adapt to our toxic lifestyles are thriving. Unfortunately because they thrive on toxic and live among us, they have an opportunity of making us sick from the very toxins we produce. Read this page on the New York Government website for more info (cause you can imagine their pigeons are mad nasty):
http://www.nyc.gov/html/doh/html/epi/epi-pigeon.shtmlOn my island they are an invasive species that are threatening native and endemic birds by taking their nesting spaces and, in addition to eating human crap, compete with native and endemic birds for other resources on the isle. Due to the high humidity and constant warm weather, harmful fungal growth on pigeon droppings pose a hazard to people. As a matter of fact, there is a removal program and if I see a pigeon nest I am suppose to report it so that they can flush it out.
I don't agree with sticking pins through their heads. To me that just sounds like someone who is, based on case studies, practicing to be a future serial killer:
http://www.criminalprofiling.ch/character.html. They target pigeons because since they lack access to a rural setting where animal killing can be done in privacy without reaction, they are left to hunt for animals people don't give a sh' about (if they did this to a puppy, this individual would probably be caught already). Pigeons may be on the forefront but I'm sure they're doing it to rats and gators in the sewer too. Most people would probably think good riddance. So, I hope they find this individual and get them help. Violence in return would be HUGELY hypocritical though, a sign of barbarous people treating barbarous individuals who are a product of a barbarous society.