The ubiquitousness of no-brain-required social networks and mobile apps has made many people forget, or never learn, a boring truth of digital life: a LOT non-ephemeral online communication still happens via less glamorous, but much more effective tools like email and mailing list. This can have unintended consequences. It is in your interest to understand this, because it is still almost impossible that you can live an adult life without using email at all, and it will be so for a few more years, at least.

True story: there is this online community which uses a public mailing list for mutual support, especially for newcomers. Their website tells these people to ask for help to the email address of the mailing list, making very clear that it is a public list. Some time ago, somebody wrote an email to that public mailing list, asking to remove from the website a file containing his phone number and other personal details. He (let’s call him John) was right, so list members tried to understand how such a file could have been published. Eventually, John came back to ask (synthesis mine):

  > Thanks for deleting that file. But why are all the email we exchanged
  > about it posted online? There are over 8 messages from this thread. Please
  > delete all of them, so they aren't visible anymore from the web, and
  > to search engines.

This is what I answered to John privately. I am posting it here now as general advice for anybody else in the same situation:

John,

The archives of that mailing list have been 100% public since the day it was created. This is also explained (enough or not, that is another issue, again totally outside my control) in the web pages where you first found the address of the mailing list.

As it happens for pretty much all the other public mailing lists in existence, the “official” public archives are continuously, automatically, integrally copied, for several reasons, by several websites, each independent from all the others and from the one that hosts the mailing list. That’s how public mailing lists and the internet in general normally work.

So of course there are “over 8 messages”: by posting a request to a public mailing list, you started a public, publicly archived conversation. And NO, I or anybody else cannot remove anything at all at this point. You would need a court order to force the administrators of all those archive copies to take the conversation offline. In theory, that is, as in “if they all live and operate their servers in countries where they must comply with whatever a court of your country orders.”

I suggest that you urgently show this and the previous messages about this issue to some friend or colleague who understands how these things work, and ask her to re-explain what I have just written face to face, in more detail. It is in your own interest to know more about these topics to handle similar issues in the future.