Q:

Many questions deleted overnight at exactly the same time

A few questions I answered to and got upvotes for have been deleted overnight at exactly the same hour and minute.
Has there been any general deletion done that would have deleted a considerate amount of questions?
Here are links to those questions (only visible to 10k+ users - thanks @MartijnPieters):

adding a form in my validate, and it will not work
Add an li-Element with the actual post-title in wordpress-menu and set it as active, when site isnt al link of the menu
According to the php documentation, when I use var_dump($_REQUEST), I should not be able to get the elements, but I do
Open/Close menus manually?

A:

In your case, all 4 of the posts were questions you suggested edits on (you didn't lose answers), but were later deleted due to a negative score and having no answers with a positive score.
See How does deleting work? What can cause a post to be deleted, and what does that actually mean? What are the criteria for deletion?

The system will automatically delete unlocked, unanswered questions that have negative score after 30 days.

(2 had answers, but those were self-deleted shortly after posting).
All 4 posts were without answer by September 30th and were deleted by a batch process. Do check out the linked FAQ for other ways the system will automatically delete posts; many of those reasons would be processed in batches.

