An employee who is serving their notice period is still an employee. Unless you mean truly ex-employees who still have access, in which case the company has a big problem if it cannot revoke credentials.

This is a strange sort of self-fulfilling prophecy. Effectively, your argument says that if there is any step, whether wise or foolish, kind or cruel, that some take, all must take it or risk being found negligent.

That's no way to run an (overly litigious) society.

I don't even agree with the self-proclaimed legal experts in the replies.

Employers generally assume liability for torts (civil liability arising from wrong-doings) vicariously. For example if an employee somehow puts rat poison into a customer's burger, the employer is automatically liable for that, because they are responsible for the employee's actions. (See eg. https://en.wikipedia.org/wiki/Vicarious_liability )

But if on the other hand a recently laid-off ex-employee sneaks back to the restaurant and then adds rat poison to the burgers, the liability of the employer isn't automatic (you can claim they should have done better with their security etc., but it is probably a defense to say they did all reasonable steps to secure the facilities).

So yeah, I call bullshit. More likely is that the C-suite just cargo-culted some "layoff best practices" and it just became a thing you did without questioning.

I generally agree with you and the parent on this. It definitely is self-fulfilling. Because some companies cut access to laid off employees immediately, it makes the others look negligent if they don't. I'm not trying to say I think this is correct or the best, just trying to speculate why some employers choose to take this action. Certainly all don't, but it does seem more common the larger a company gets.

I'd be curious if every laid off Google employee experiences this hard cut off, or if it's determined case by case.