[drakeandrews]

In a lot of cases (at least in the UK), it could fall under gross misconduct, for which your employer is allowed to terminate you on the spot. Of course, you can then take them to an employment tribunal who will then deliberate on if this was appropriate.

[waterlion]

Yes, gross misconduct is a valid cause for termination. I think an employer would have a very tough time justifying behaviour like this.