I replaced all my comments with the same phrase before deleting them with PowerDeleteSuite. The comments were fully restored and visible through a google search (but not visible through the user page). My posts were not restored, AFAIK.
This was during the whole 3rd party API thing. Maybe it was just something done during that time, but they certainly got around the edit replacement trick before.
And to add, they will only fight if they have an unfair advantage (more people, better weapons, etc). It’s better to defend your own ground if necessary.