I'll just add one point to my colleague's excellent explanation.
Copyright protects the *expression* of an idea, but can't protect facts. If the original expression is
Ryan: That sweater that Suzie knitted for me is the bomb.
Mallory: It makes you look fat. Anyway if you don't stay away from Suzie I'm going to break up with you
Suzie: I don't see any ring on your finger, loser!
copying verbatim in whole or in part would infringe on the copyright of the original author. Assuming, however, that this is not a work of fiction and is an accurate account of the facts, you could probably comment that "Suzie is interested in Ryan, which makes Mallory jealous" without infringing on the copyright of the source. The idea that Mallory is jealous is not protected by copyright.
If the terms of service prohibit such commentary or disclosure regarding the content of the site, of course you can't do that. And if the subject matter is fiction and the characters of Ryan, Mallory and Suzie are someone else's creative work, then you might be violating that author's right in derivative works by expanding on those characters.
As always, if you're just not sure, listen to that apprehensive inner voice and consult with an IP attorney. It's a lot less painful than getting sued.
This reply is not and should never be considered
"legal advice." If you need legal advice, consult
a licensed attorney in your state to make sure you
understand both your state and federal laws concerning
your issue. Your attorney will need specific and
complete facts to provide you with legal advice.
No attorney-client relationship has been created by this reply.
Copyright Infringement and whether a "fair use" defense applies to such a claim based on someone else's work, is fact-specific and depends on an analysis of 4 fair use factors, one of which is how much you use of the original work.
If the original work's site expressly disallows copying, then you're on notice that that site claims all rights to its content and that you can't copy it. you can't a definitive answer from anyone who hasn't reviewed the original work and your proposed work, sp see an IP lawyer.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.