Corrupt your text

caseshift.py

import sys
import random

if __name__ == "__main__":
    for line in sys.stdin if len(sys.argv) < 2 else open(sys.argv[1]):
        for char in line:
            if char.isalpha():
                sys.stderr.write(char if random.choice([0,1]) else chr(ord(char) ^ 32))
            else:
                sys.stderr.write(char)