Data recovery (was: Re: SETI at home (ca. 2000) servers heading to salvage)

[Jules Richardson]

On 4/3/22 10:51, Eric J. Korpela via cctalk wrote:
> drive removed and destroyed for privacy reason.

For those in the know, how much success - assuming a "money is no object" 
approach - do data recovery companies have in retrieving data from drives 
that have a) been overwritten with zeros using dd or similar, and b) been 
overwritten with random data via a more comprehensive tool?

cheers,

Jules