"Stole data for employees" vs "stole data of employees"

Question

Thief Stole Payroll Data for Thousands of Facebook Employees

[link]

Why use "data for" instead of "data of" ? Isn't that "for" means "data given to" and "of" means "data belong to" ?

Answer 1

“Stole data for employees” is ambiguous when considered as a standalone quote with no other information. It could mean the data was stolen to give to the employees, but experience would suggest this as an unlikely situation. Alternatively, it could mean the data which was used for managing the employees. The latter seems a more likely situation (who steals data for employees?) and the choice of wording is unusual.

“stole data of employees” is unambiguous. It means the data belonging to the employees. Of course, this could be written some other way, e.g. "stole employee data", "stole employees' data", etc.

By reading the linked article it is clear that “Stole data for employees” in fact means the employee's data was stolen. The full title is ambiguous ("Thief Stole Payroll Data for Thousands of Facebook Employees") but can partly be explained by the first paragraph in which "for" is used without ambiguity:

Personal banking information for tens of thousands of Facebook Inc. workers in the U.S. was compromised last month when a thief stole several corporate hard drives from an employee’s car.

So, to answer your question, namely why use "data for" instead of "data of", it's because the writer used "information [data] for" in the opening paragraph and chose to be consistent.

Answer 2

The quote below says that the thief stole data on behalf of thousands of Facebook employees.

Thief stole payroll data for thousands of Facebook employees.

This quote says that the thief stole the data belonging to thousands of Facebook employees.

Thief stole payroll data of thousands of Facebook employees