I'd put your banner back up for sale, and respond like this (seriously, and the part about copyright of a phrase is true):
Dear (shop owner):
thanks for contacting me about the "you do you" banner in my shop. I respect any artist's desire to protect their unique artwork.
In this case, I had never seen your shop or your artwork. I was not copying you, instead I was inspired by that phrase due to something I experienced personally.
In this case, the phrase "you do you" already belongs to a band, a song title, and has been used by many artists in their work. It is not attributed to a single person.
Copyright Protection is not available for names, titles, or short phrases - - you can copyright a brand name or a trademark, but not a general short phrase. Just like I can't copyright "I love you" and try to stop everyone from using it, the phrase "you do you" is also in broad use. It's even in the Urban Dictionary.
The one thing we can do as artists is respect each other's designs, use of colors, shapes, fonts, etc. I agree with that totally!
I certainly don't intend to copy anyone's work! I understand how you feel. However, my little banner was created out of my own imagination and creative flow, so I think we are okay. If you have managed to copyright and protect the phrase "you do you", you might want to start by contacting the band of the same name first! I'm just a little Etsy shop with a single banner with those words.
Good luck with your Etsy sales and artwork.
