It is only immature people who believe, “I am separate; therefore, I can manipulate you, even exploit you, to ensure my own happiness.”
We see this play out with internet trolls, even so-called friends who like to send us things or post things to get a rise out of us. Do not let someone else’s misguided immaturity steal your peace. See them and their tactics for what they are; notice what arises in you when they attack and let it go.
This will take practice at first and take time to reverse a lifetime of habitual thinking, but you can do it and in much less time than you think.
Remember that no one has any power over how you feel. Your upset comes when you identify with what is said or seen; mission accomplished said the troll. No matter what enters your space or thoughts, remember you have the power and control, not them, and not your mind. No one can take that away from you, except the one who thinks it.