Detect if an Author has deleted history

[FoxxMD]

Users can delete their history. Sometimes this is done for privacy reasons and sometimes its to cover their tracks for spamming, using freekarma subs, etc...

Being able to detect if they have deleted history could be a useful signal but current methods/data have some limitations:

Reddit does not provide a total count of submissions/comments a user has made, only their total karma

Checking karma against history would work but only for users with limited history -- EX where this would fail is if a user had 500 activities but deleted the past 6 months (50 activities). CM would have to get all 500 which would be expensive.

Additionally, it wouldn't be able to tell the percentage or what part of their history missing, only that karma did not match up with numbers on profile.

Does profile karma includes activities in private subs?

I couldn't find any documentation about this. If the profile karma includes stuff from private subs then it would be inaccurate to assume mismatched profile karma with history means deleted posts.