I should’ve been more clear about my question, how would I, as a lemmy user, know if an instance has gone rogue (taken over by another entity, meta/fb/ig).

Excellent question (due to the primary methods of how these companies hide their malfeasance)! The answer is in two parts:

1. You wouldn’t… at least, not directly: Like many diseases, drug tests, or with identity theft, the only way you’d know is by way of detecting the “traces” or after-effects of it. What companies like this do - steal your personal data for their own profit - does not necessarily have a negative “primary effect*, but has a long-term secondary effect. That is, you aren’t negatively affected immediately, but, over time, these companies use your personal and private information to manipulate and take advantage of you for their own profit. It can be leaked or hacked due to their own irresponsibility or cheap security measures (or mistreated employees) and your money can gets stolen (or worse), and you can have your identity stolen or worse. All of these things have and continue to happen, and stronger and more comprehensive laws to protect against this sot of data and privacy failures at the corporate and government level are working through various governments as we speak, but… we also must work together to ensure that open-source solutions and communities do their best to ensure community and personal data privacy are enforced in the meantime.
2. Meta and Twitter, another private companies have realized years ago that private data is the most valuable type of data. These companies will and have done everything to use any method at their disposal to guarantee their everlasting access to it. They are unscrupulous and unrelenting. The Fediverse is an open and open-source response to this trend, a viable alternative to everything from Facebook, Twitter, Reddit, and every other form of social media. As a result, ever form of corporate social media will and has targeted for EEE, that is Expand, Engulf, Extinguish (as addressed above), for it is recognized as the next-generation of online platform for communicative discourse/interaction.

so, the iterative control/model relationship is about to be wrestled out of the control of major corporations for the first time and major corporations are about to fight with the public over that. we’re about to see if that’s something which is realistic.

I wonder if there could be precedent set if a collective should come forth and file an antitrust lawsuit.

edit: this would all be very unprecedented, and the last time this happened wa in the 90’s, and I was on behalf of Netscape by the DoJ, so… I dunno. It was weird even then.

They don't even need to go that far. All data on lemmy is publicly available to anyone. You don't need an instance or even an account. Defederating from meta/threads won't stop them from reading all data out of the fediverse.