In the US, Spain and Argentina, there are projects that show red and yellow cards to abusers and harassers when people are harassed on the streets. Here are the cards:
Many see this as a non-confrontational way to approach a harasser. You could carry around a stack in your backpack or purse and hand these to people who are aggressive to you. While they are reading you can get out of that situation! Do you think this would work in Istanbul?