The opinion doesn't mean they can't be held criminally liable for anything they do with access to that system, just that the CFAA isn't the law that is broken. That means that the punishment or restitution imposed, if any, has to do with some other harm that was caused, over and above the mere fact of, for example, your "intrusion" into Facebook's computers by posting a photo of a cartoon character and thus violating Facebook's terms of service.
In your gay-hookup-website example, you might be civilly or criminally liable in various states of the US under a variety of laws that have nothing to do with computers. For example:
· an invasion-of-privacy tort or negligent-infliction-of-emotional-distress tort due to publicly disclosing private facts about the plaintiffs;
· a breach-of-contract tort or tortious-interference tort or negligence due to damaging your employer's business relations with the users (especially if you signed an NDA);
· a misappropriation-of-trade-secrets tort arguing that the users' information is a "trade secret" of the employer;
· a breach-of-fiduciary-duty tort claiming that if someone was going to get paid for the users' information it should have been your employer and not you;
· a breach-of-confidence tort claiming that your employer owed the users a duty of confidentiality, and you correspondingly owed it to your employer, and that you breached it by selling the data to journalists; or
· a conversion tort because you used the computer system in a way you were not authorized to use it.
(Also, the employer can probably recover whatever you were paid with an unjust-enrichment tort.)
Aside from being a tort, trade-secret theft is also a federal crime, so if your employer can persuade a prosecutor to go after you, they may be able to get you jail time. IANAL but I think the trade-secret case here is kind of weak, because in your scenario I think the journalist isn't running a competing gay-hookup website, so they aren't competing with your employer. There's also a crime of "criminal conversion", which I think is also kind of a stretch, since the employer can still use the computer system.
However, there was a civil conversion award for conversion of computer programs in Alabama in 01978, and another for conversion of personal information in New York in 02007: https://www.law.cornell.edu/nyctap/I07_0029.htm and in Oregon in 02013: https://www.tradesecretslaw.com/wp-content/uploads/sites/232.... Such innovations are still controversial and not widely accepted: https://www.nortonrosefulbright.com/-/media/files/nrf/nrfweb...)