Digital tattoo
Overview
A digital tattoo is the phenomenon in which text, images, videos, and other information once published on the internet keep remaining as copies, caches, or archives even after the person who posted them deletes them. Just as a tattoo inked into your skin can't easily be removed, it is practically impossible to erase information online completely.
Unlike a digital footprint (browsing history and logs left unintentionally), a digital tattoo focuses on information you actively put out becoming impossible to erase. Social media posts, question box answers, and posts on message boards can all become digital tattoos.
Why it doesn't go away
There are three technical reasons. First, search engine caches. When a copy of a web page has been stored, the cached version can remain even after the original page is deleted. Second, web archives. Services like the Wayback Machine regularly save snapshots of the whole web. Third, screenshots. If someone takes a screenshot and posts it somewhere else, deleting the original post does nothing.
Question box answers are no exception. Because there's a culture of screenshotting answers and sharing them on social media, even if the person answering deletes an answer later, there's no undoing it once the screenshot has spread.
You publish an answer in your question box
The moment it's published, anyone can see it.
You delete the answer later
It disappears from your question box, but you can't chase down the copies that have already been made.
Search engine caches
A copy of the web page is stored and remains even after the original page is deleted.
Web archives
Snapshots of the whole web are saved regularly.
Screenshots
If someone takes one and posts it somewhere else, deleting the original post does nothing.
The copies keep remaining elsewhere
Question boxes have a culture of sharing answers as screenshots on social media, so there's no undoing it once it has spread.
You can't prevent it completely. That's exactly why the habit of pausing for a moment before answering to ask "Would it be okay if this spread?" works.
Protecting yourself in a question box
You can't prevent digital tattoos completely, but you can lower the risk. The habit of pausing for a moment before answering to ask "Would it be okay if this answer were screenshotted and spread?" is effective. The more emotional you are, the more likely you are to post something you'll regret. An answer written in a late-night mood turning into dark history by the next morning is a common story.
Thinking "It's fine because it's anonymous" is also dangerous. Even with anonymous posts, the person can sometimes be identified from their writing style or content. You always need to keep in mind that "anonymous = safe" is not true.