[insulanus]

I don't agree that just because some content is in Reddit's database that they "own" it, but let's set that aside for a moment.

Even if we allow that Reddit owns all content in its database absolutely, they are also making an implicit representation that what is in the database is what the user actually typed. A poll of all reddit users asking "do you expect what is shown to be what the user typed?" will come up "Yes".

I imagine the outrage felt by those reddit users is not for this violation, which is small in scope, but for the realization that reality can be changed out from under them, and the uncertainty about that power asymmetry being used against them.