It depends on the legislation, but in general: NOPE. You have to treat stolen data as a stolen object. Even if you get them by legal means (eg a robber sold yo

It depends on the legislation, but in general: NOPE. You have to treat stolen data as a stolen object. Even if you get them by legal means (eg a robber sold you a "you didn't know" stolen object with a legal contract) it still remains a stolen object and as soon as you discover/know it is stolen you must return it to authorities or the proprietary. In EU for the data you must get the consent even in third party "reselling" even if you already had it for your own use. If stolen there is no way you could use that data legally because the property is both of the users and of the company/entity from which they were stolen and you are not authorized to treat it in any way. It is different if the data is public domain/interest (eg for the case of the journals, they just release data that authorities made public). But, indeed, an authority must decide so