Shots fired! Well, the shots were fired by Real Madrid in the first leg when they displayed a banner that asked, "How does it feel? Lisbon - Milan". Atletico will respond with their own tifo on Wednesday night saying, "Proud to not be like you", according to COPE.
Atletico Madrid have already responded with their own social media campaign centered around the message "Know how to win, know how to lose #YouCantUnderstand" and they have been systematically posting messages about values leading up to the game.
UEFA ask the clubs before the game to show them the banners so they can approve and the message they display. They have the final say on the tifos, which should not include political, commercial or anti-disciplinary messages.