[Matrix exploding with Element securing $30M funding to revolutionise the app’s usability, build out major new features, expand in the enterprise market and take Matrix fully mainstream!](https://element.io/blog/element-raises-30m-as-matrix-explodes/)
[Element iOS hides them completely with the exception of notifications that cannot be acknowledged](https://github.com/vector-im/element-ios/issues/5455).
Yes, privacy is a big reason why Matrix is advertised and the lack of it is a
fact you agree to by using Matrix or getting bridged to Matrix (which is out of
scope for this blog post as it involves other protocols too much, whether you
know Matrix or not).
As with the internet in general, the most safe assumption is that once you post
something it's there forever. It may be encrypted in a private Matrix room or it
may be public in a public room, but it will most likely be there forever.
Matrix does support
[history retention if you are advanced enough to enable it](https://brendan.abolivier.bzh/matrix-retention-policies/),
this assumes
[your homeserver explicitly enables it as it's not default](https://github.com/matrix-org/synapse/blob/ba5287f5e8be150551824493b3ad685dde00a543/docs/sample_config.yaml#L481-L484)
and as your room is hosted on every homeserver that has users in your room, have
a single homeserver that hasn't explicitly enabled it, or doesn't otherwise
support it, and the room history never goes away. Executing
`/upgraderoom {{site.matrixLatestRoomVersion}}` or any other version
[will also remove the event](https://github.com/matrix-org/synapse/issues/11279).
**_WARNING!_**
[Enabling history **_retention_** may **_corrupt your Synapse database_**](https://github.com/matrix-org/synapse/issues/13476)
and
[will make your room **_unrejoinable_** if a homeserver leaves it for long enough](https://github.com/matrix-org/synapse/issues/11448).
Upgrading the room will fix that, but it's just a fancy way of saying
"discontinue the old room and add a note saying where the new room is".
**_WARNING! Always before executing `/upgraderoom` check that everyone in your
room has a recent Matrix server that supports your target room version,
otherwise you may lock some of your users out._** For example
`/invite @version:maunium.net` and once it joins, say
`!servers upgrade {{site.matrixLatestRoomVersion}}` to get a list of servers
that don't support room version {{site.matrixLatestRoomVersion}} yet.
In case there isn't enough confusion, retention shouldn't be confused with
_Technical note: sorry about calling <s>reference</s> homeserver implementation
by the <s>matrix.org team</s> New Vector Ltd issue as a Matrix protocol issue._
You may say that this requires you to trust the homeserver admin anyway and that
is true, I wish people could trust each other and even if someone modified their
Synapse to never remove anything or had a client logging everything, they
wouldn't throw that history to people who don't want to see it.
Speaking of removals, once you remove a message
[it will be stored in the database for server admins for 7 days](https://github.com/matrix-org/synapse/blob/ba5287f5e8be150551824493b3ad685dde00a543/docs/sample_config.yaml#L456-L461)
which is fine for me, but if
[this message happened to be media instead of text, it would never be removed](https://github.com/matrix-org/synapse/issues/1263)
and should you have copied link to the media, it would keep on working and if
you changed the homeserver address in your copied link, it would still keep on
working. Is this something you expect from a private protocol? I don't, or I
didn't before getting familiar with Matrix. There is also an
[alternative proposal about this](https://github.com/matrix-org/matrix-spec-proposals/pull/2228).
_By the way Synapse is still a <s>reference</s> homeserver implementation by the
<s>matrix.org team</s> New Vector Ltd and not Matrix protocol itself, so sorry
professional context, a nickname somewhere else and maybe what will be your real
name after gender transitioning or even have a diffferent name in direct chat
with your partner?
[Congratulations, whatever is your latest room-specific name may now be public (especially when the room federates and has users from different homeservers), same with your potential avatar](https://github.com/matrix-org/synapse/issues/5677).
_Synapse didn't become Matrix protocol itself by the way, there are still other
implementations!_
This issue does have a potential solution
[an API planned for room specific details (2015)](https://github.com/matrix-org/matrix-spec/issues/103)
- [Changelog, also known as git commit history](https://github.com/Mikaela/mikaela.github.io/commits/master/blog/_posts/2021-08-03-matrix-perfect-privacy-not.md)
