Legal to write on money

i write messages on my money in the white margin. usually poetry or some political statement. do you thijnk the feds will be harassing me>

I suspect the Feds have more to do than investigate poetry or politics on a dollar bill. My problem is understanding how brain dead someone would have to be to change the way they vote based on what they read there. Isn't there somewhere you could publish your ideas where they would be taken more seriously?