I disagree with some of you (even though I would never register a domain like this, mainly to prevent unnecessary headaches and timewasting in general). However, Sheries11 might be able to challenge this "case," plus there is no legal obligation to delete the domain or surrender to Facebook in the first place (regardless how strongly many of you feel about this).
David vs. Goliath rules/laws and fair use of copyrighted/trademarked materials (in order to publicly share objective reviews) rules/laws allow all of us to (even knowingly and/or purposefully) quote any third party website (whether it's trademark protected or having just default copyright protection) in order to review its offerings/problems/policies and/or to gather support/vies of other harmed customers/users/employees/ex employees. In certain circumstances, e.g. when the site/company doesn't have a functioning Contact Us form/email or similar option and/or if their policy is to ignore customers/ex employees who they consider bothersome, one can even make a website just to get their attention and/or to solve issue(s) or financial problems, for example getting reimbursed, compensated or to simply receive an apology. If no standard communication channel exists and/or if previous communication is not replied to, and especially when the company/site uses a whois shielding option, meaning their visitors/users/clients cannot even send them a physical letter (knowing how to look up a registered business address any other way is not essential, i.e. complex gov registries or Company House sites don't have to be searched/signed-up to), making a "public scene" site had been accepted for both ventilation of feelings and resolving problems (the courts are fairer than most corporations want you to believe).
Even while being able to contact the questionable company properly, you could (and still can) register FacebookSucks.(whatever) or FacebookRocks.(whatever) and post any critical points or praises you want (within the scope of the law). Once you do that, even if the company might send you well-worded request to take the site down, delete the domain name, etc., you are actually going to be protected by numerous laws and rules. No giant corporation, regardless of the size of their legal budget, will be able to automatically silence you. (Contrary to popular belief.)
It's a different story if you register(ed) a/the domain in bad faith, and especially if you offer(ed) a/the domain to its prospective (i.e. de facto intended) buyer. Then you will be looked at like that dodgy guy/gal in a dirty reflective vest who "offers" to look after someone's car while being known to damage vehicles of those drivers who principally refuse to pay him for his/her informal (and therefore questionable and, most importantly, tax free) services. You will considered the same vermin/parasite, and you will likely be labelled a scammer by ever the most reasonable judge. No worries, you may say, I have some strong arguments to present my case. Tough luck, nearly every judge will dismiss your (however valid) points based purely on the bad faith factor (manifested by your initial action(s)). Your case will be thrown out (or you will be locked up) before you even start presenting your cleverly worded counterarguments.
Unless you wish to criticise (or prepare class action against) a company, or praise it - which is of course not an issue, you will be facing certain issues. However, should you wish to merely tell them that they suck (and invite others to do so, as long as positive (re)views are not deleted by you), you will be as safe as if the following big companies established the these hypothetical pages: ebaysucks.trustpilot.com and ebaycomplaints.bbb.org (or even if they/you openly or stealthily registered ebaycomplaints.whicheverextensionisavailable). The same goes for FB, Google, Apple, Chinese government or any other we-are-stronger-than-you dreamer/company/gov. They are not necessarily stronger than you. On the contrary. In the court of law, you will be given more rights while they will have to pay for every piece of advice they receive from their in-house or external team(s) of lawyers, yet you will be able to dismiss some of their this-took-us-weeks-to-prepare statements with just a sentence or two. Most courts like small but daring Davids, and they like pissing off big companies, especially the ones who are too cocky and/or believe they can bribe or threaten any individual/judge/system.
Quoting specific company statements/emails/physical letter/in some cases calls, even those from their corporate lawyers (only certain exceptions apply), showing their logo, screenshots, etc., all of this is protected under the rules/laws of fair review usage. It's like if you were video recording a thief, (s)he may challenge you (privacy protection and many other laws) but your case will be solid, unlike his/her case (illegal activity versus your acceptable action in regard to his/her/their committed/perceived/expected illegal activity). The same goes if you are a whistleblower employee/customer, even if you install voice/phone bugs and hidden video surveillance system(s), as long as the offending company did/does something wrong and the "Davids" like you are merely preparing to prove the illicit/unethical/wrongful action(s)/inaction(s)/offence(s) in the court of law, they (just like you if you are a whistleblower or someone with a valid complaint about an illicit action) will be protected more than the corporate giants they/you are fighting. Unless prevented by a whistleblower protection act, the judge will likely question each David's action and the offending corporation might challenge those Greenpeace-like actions and websites like there is no tomorrow, but the whistleblowers/you will be fine, or they/you will be able to take it to a higher court where uninvolved/objective judges don't believe in corporate-court buddy/corrupt options as much as lower level judges might. Even if the higher level judges are dodgy themselves, all the Davids (or you) have to do is to go public. Even the most corrupt judges generally start making right decisions when facing public scrutiny. They need PR too, and protecting certain smart Davids is essential for their public image (even if they usually make decisions based on subjective feelings or bribes).
Overall, unless you know that you acted in bad faith in the first place, being legally challenged/gagged is not as easy as the big guys make it appear. Don't believe in their BS, or quit (based purely on your conscience, you are the only one who knows if your action will be easily defined as fair use or in bad faith).
Hope this helps. Unless you are one of the dodgy domainers, please don't give up. Otherwise the big players will get too cosy and all of us will be challenged over silly things, even when the law says otherwise.
Cheers!