My name is Legion, for we are many

They tell me I'm wrong. They don't shut up and won't. I see them on the street and every day they follow me home, but still I am alone. They're in my head and under your bed, whispering my wrongs and chanting their songs. They tell me to tap: 3 times, 2 times, 3 times 4, lest something bad befall. I've long since learnt to ignore or do the opposite of your play, I just wish you'd stay away.