Why do you feel the need to defend Slack? It was their decision to do this to ensure they wouldn’t be forced out of the corporate market ($$$$$) and, I hate to break it to you, US and EU law are very similar in this regard. Corporations in the EU can listen to your business correspondence just as easily as US ones, and in neither do you have any real expectation of privacy at work.
You are wrong about the EU - the national legislation on right to privacy is stricter in many (most?) countries. EU only sets minimum levels of protection. And even EU law protects more than you imply(1).
I'm defending employee rights and generally the human right to privacy against arbitrary surveillance, not Slack.
In particular, the national courts had failed to determine whether the applicant had received prior notice from his employer of the possibility that his communications might be monitored; nor had they had regard either to the fact that he had not been informed of the nature or the extent of the monitoring, or the degree of intrusion into his private life and correspondence. In addition, the national courts had failed to determine, firstly, the specific reasons justifying the introduction of the monitoring measures; secondly, whether the employer could have used measures entailing less intrusion into the applicant’s private life and correspondence; and thirdly, whether the communications might have been accessed without his knowledge.
There is nothing in that case that prohibits EU companies from monitoring the communications of their employees. Half of that case revolves around legal procedural problems in the original case, and the other half is about whether the company could have fired him over his personal correspondence _without proper notice_. That case, if anything, only upholds corporate EU rights to monitor their employees, so long as they provide some trivial legal notice.
yes, EU law does protect private correspondence more than US law, but almost none of that applies to business correspondence, and the EU is just as liberal in that regard as the US.
Workplace communication between coworkers eg on Slack is not automatically business correspondence in this sense.
In any case, you repeat the oft debunked myth of corporate right to surveillance. It does not exist. There is just partial lack of EU level protections. The national laws can and do say otherwise in many cases. As can/do binding collective bargaining agreements.
