Receipts
Overview
Receipts is slang for evidence of what someone has said or done on social media. Just as a shopping receipt proves a purchase, screenshots and web archives serve as evidence of past posts. "I have the receipts" means "I have proof," and people say it when they confront someone with their past words in an argument on social media.
Question box answers become receipts
Once you share a question box answer, it may stay around as a receipt. Even if the owner deletes the post, the evidence doesn't disappear if a follower saved a screenshot. The answer may also be saved on the Internet Archive's Wayback Machine.
Getting called out for a contradiction like "Back then you said this in your question box, but now you're saying something different" happens precisely because receipts exist. Changing your opinion is natural in itself, but whether you can respond honestly when someone asks how it fits with what you said before shapes how much people trust you.
Writing answers with receipts in mind
Once you keep in mind that every answer could be used as a receipt in the future, the way you write answers changes. Definitive statements ("X is absolutely true," "X, no doubt about it") are easy to call out as contradictions when the situation changes. It's safer to choose wording that makes your conditions or position clear, like "For now, I think X" or "Just my personal opinion."
Be especially careful about what you say about other people. Judgments like "X is trustworthy" or "Y is no good" may be brought up as receipts later when the situation changes. Opinions about people change over time, and writing them definitively in a form that stays on social media carries a big risk.
What to do when someone shows you the receipts
When someone confronts you with your past words as evidence, the response to avoid is denying it: "I never said that." As long as there's evidence in the form of a screenshot, denying it just piles another lie on top.
The honest response is to admit what you said before and explain why your thinking changed. It's good to say it plainly: "I thought that back then, but I changed my mind after learning about X." People's opinions change, and there's no need to be ashamed of changing. What's shameful is trying to hide the change.