Wonder how long will it take the game companies to go after people. 🤣
In the US anyway (and this is where the copyright stuff is strictest), it will be very difficult unless people are openly offering access to ROMs or sharing ROMs in the open in their Discord -- particularly if that sharing is happening in Discord only accessible to users who pay for access.
The US case law around emulation itself is extremely settled. Like settled for the better part of 25 years settled. There are DMCA exemptions around extracting the ROM data from games you own for your own personal means (which most people don't do but ROM dumping from the systems Delta supports is extremely easy and simple at this point). Entities like Nintendo and Sony and Sega actively sell or have previously sold devices that contain open source emulators at their core and in some cases, have packaged ROM files that were clearly sourced from the community and not their own archives.
Because Delta doesn't facilitate helping people find ROMs, there is nothing Nintendo can do. The reason Yuzu was shutdown (and it was a voluntary shutdown, granted it was also part of a settlement that also required the devs to pay Nintendo $2.4 million, but it wasn't a court ordered shutdown, which is important) was because of some aspects of how they acquired their cryptographic keys (and similarly to the the 1999 Sony lawsuits against Connectix and Bleem, this portion probably would have ultimately won in court, but could have bankrupted the individuals involved) and even more importantly, because of how brazenly and I would argue, recklessly, Yuzu devs/community members shared Switch game dumps on their Discord (and access to that Discord was provided by the Patreon that the devs were making $30,000 a month on), which is something most other emulator developers strictly avoid at all costs.
Now, if someone is dumb enough to brag about their iCloud or Dropbox or Google Drive full of ROMs and pass links to their libraries all over the internet -- yeah, Nintendo will probably DMCA them and get the content kicked off of those respective cloud services (and the user will prob be banned too). And obviously,
running ROM sites or
aiding in the distribution of piracy tools is a very bad idea. But merely using ROMs obtained elsewhere? People who know the first rule of piracy club are going to be fine.