How to gently acknowledge and inform a person:
Check their blog/content/about me. How old is this person? If they are still in HS/under 18, remember that this person is a minor and needs guidance, not chastising.
Second, look at a little bit of their tumblr. Are they going through serious mental health struggles(Depression/suicide/etc)? Please take this into account when formulating your response.
Finally, evaluate why you follow this person to begin with. Now, if you are 19 and following a 17 year old, then you are within the same age bracket and can talk to this person as if you are talking to a peer. 12/13/14/15 year olds are still formulating their opinions of the world, and you being nasty to them isn’t going to help inform their opinion. So why do you follow a 13 year old? Would you hang out with this person IRL if you two were in the same location? Would it be weird(mentally and physically) for you to hang out with this person? If the answer is yes, unfollow their blog and step away from the situation.
NOW, here is how you formulate a PRIVATE ASK OR FAN MAIL to someone who has said or done something problematic. Shaming them publicly for ignorance/limited world view is a great way to close someone off or harass them, and you don’t want to do either of these things. Online bullying can take on many forms, and being an adult harassing a young teenager adds to online culture problems
“Hey! I noticed that you reblogged (x). I wanted to let you know that this is really hurtful to (x) group, and it is offensive because of (x) reason. I just wanted to let you know because you may not have known. Thank you for receiving this message and listening”
This points out what is wrong, why it is wrong, and does not demand anything of the person you are sending this message to
And then you step away. Do not send this person 20 asks. Do not threaten them. STEP AWAY.
If they engage, respond, or ask further questions, answer them kindly. If they don’t respond, don’t continue to engage.
REMEMBER: you were 14 once too. You said and did things that you cringe at now. You said and did things that were problematic. Getting yelled at was not what you needed. You grew up, you learned, you changed. Let others do the same.