Talk politics.

It's a stupid move by the Romanian company. First of all it's not so easy to find good qualified personnel, and the cost of recruiting and training new people is rising. Second, the engineer didn't do anything wrong so why invoke personal usage of a messenger service as the pretext? If they have some real beef, they should spit it out rather than hiding behind the pretense that they can own people 100% of the time. And looking at someone's chat is the kind of douchebag move that just reeks of arrogant stupidity. Third, I know the Romanian companies generally pay crap so they probably did him a favour by forcing him to look for much better work conditions elsewhere.