[gbl08ma]

Not to mention, that for many of these destructive actions adding a undo function often incurs in higher storage costs.

For example, in the case of deleting information, the easiest way to provide an undo function is to never really delete anything and just flag as deleted (something that doesn't free up storage, and if implemented without the users' knowledge, is abusive in terms of data privacy and ownership).

As for users not expecting the existence of an undo button in a web context, well, Gmail for instance has an "undo" link for lots of actions (archiving, moving to trash, etc.). I'm sure other web services provide similar things too.

[fixedd]

Just clean it up later... flag as "delete in 1 day" or something.