Title should be editable for at least a few minutes after a post, up to maybe an hour at most. Anything after that, it becomes a method of slipping shit past the community by masking it as something else, or changing it down the road to fuck with search engines.
Also, it increases the amount of work mods have to do by not only monitoring new submissions but having to continuously monitor old ones for edits.
At the very least, edits to the title should not overwrite the original after a short grace period but instead be considered "alternative" or "additional". You can add onto it (i.e. Update: Cat has received scritches), but you can't alter the original.
I know we all hate Reddit for obvious and understandable reasons, but not everything it did was stupid. This is one of those things where the restriction was to both protect users and prevent abuse, not just because Reddit is mean and doesn't like users.
Maybe have it be something that can be set per instance/community, and/or up to operators/moderators, like how downvotes are currently configured?
That way, mods that don't mind it can allow it, and ones that don't want it can remove it.
Although some way to be able to check and revert changes would probably also be handy, just in case of a malicious/accidental edit, whether due to a malicious user/operator/moderator, a bot going rogue, etc.
Titles being editable is really useful. So many posts have misleading titles, causing posts to have to either get removed or flaired (I don't think we have an equivalent of flairing yet).
Plus, unless we're prohibiting editing the body or even comments within posts, it has similar risks to editing the title or URL. Though the post URL is the one most likely to get clicked and thus is the highest risk.
It is something tooling could help detect. Moderator tools could detect posts changing the URL and flag the post for review. The general idea of spam filters apply well here. Spam filters aren't just for completely preventing spam, but also for flagging potential spam. We could train spam filters on diffs of comments so that they can recognize when posts seemed to have completely changed in a way that we'd classify as spam.
But at the same time, letting the title be edited can also cause problems later on, especially if it's something that can be used to feign support, or something along those lines, on something a bit more malicious.
It makes it a little bit easier to do, but it is not difficult to replicate this effect without changing the URL in the title - using a redirected URL and changing the redirect address, for example.
I think that this small increase in the way this kind of attack can be delivered is more than counter-balanced by the convenience of having editable titles.
You don't need to use a known redirect link. If the plan begins with a post that obtains 10,000 likes, I am sure the attacker can spend a small amount of effort and register a domain.
Reminds me of a long time ago when GameSpot and GameFAQs forums merged. GameSpot users had the ability to edit titles so they would have threads like "what's your shoe size?" Then they would change the title to something like "how old are you?" to get the GameFAQs posters banned (due to the minimum age requirements)
I see what you are doing here. But being able to edit title is so convenient, I couldn't live without it.
Maybe add a heads-up notice saying the URL has been specifically edited after some time has passed since post creation? e.g. Two hours?
Or do something like what Twitter is doing now, letting users add specific context on the title notifying people about what changed, even confirming misinformation?
Or always crosscheck the hyperlink in title or body with an open-source malicious site database and flag all malicious sites once and for all?
In addition to what was suggested before, editing the title could disable hyperlinks in the title, adding anotger layer of protection from malicious edits.