Why is it currently illegal? If I have a service that let's users communicate, why is it illegal to look through those communications? (especially after they've signed my 400 page EULA). It would make moderation impossible otherwise.
Or are we saying this is being used for something specific that happens to be illegal?
> Why is it currently illegal? If I have a service that let's users communicate, why is it illegal to look through those communications?
Not all services should be treated equally. We've figured this out earlier about letters, it's typically illegal, even for postal services, to open and read your letters without your consent, because there is an expectation about privacy.
Fast forward some years since then, and now basically IMs are the new letters, and sadly we have few big actors (yet again) controlling the transportation of our communication. People generally still want privacy in their communications, so regulations were made that companies cannot open your messages ("letters") without your consent, so we humans still have more or less the same protections as before, just tailored to the new specific implementation.
It guarantees that the content of sealed letters is never revealed, and that letters in transit are not opened by government officials, or any other third party. The right of privacy to one's own letters is the main legal basis for the assumption of privacy of correspondence. The principle has been naturally extended to other forms of communication, including telephony and electronic communications on the Internet, as the constitutional guarantees are generally thought to also cover these forms of communication
Moderation is when others remove publicly posted content because you don't want to see it. (Censorship is when others remove publicly posted content because they don't want you to see it.)
You don't need moderation for your private communication.
Why should you have any right to look through everyone's private communications? Nobody really has any choice to reject your EULA if they want to stay in contact with someone on your service. I could force you to sign a ToS that includes "By using our service you owe us $10 million and agree to donate your kidney to our CEO" in order to reach your overseas grandma, but that doesn't mean it's actually enforceable or legal...
People sending unwanted DMs is an obvious reason. At the very least, users should be able to report DMs and then that should allow for moderation.
It's very common in some spaces to get people who send unwanted (spam/harassment/etc) DMs to tons of people. Just expecting everyone to block those people makes for a horrible user experience, because it means new users might be suddenly met by a bunch of unwanted DMs from aggressive randos that remain unbanned. You really need to be able to ban these people (and that means being able to verify that they did what they're accused of).
In some EU countries it is not only illegal, but also unconstitutional.
For example, Art 15 of the Italian constitution [1]:
"Freedom and confidentiality of correspondence and of every other form of
communication is inviolable.
Limitations may only be imposed by judicial decision stating the reasons and
in accordance with the guarantees provided by the law."
Or are we saying this is being used for something specific that happens to be illegal?