Regardless, this is a real world. Scam exists, even the world's famous auction site, eBay has fraud, politicians do fraud.
Nevertheless, many methods does exist to proof things. Digitalpoint has got the tradition of providing review copies, but I'll leave to the Admins and mods to decide for that themselves.
Freedom of speech exist, but it is not without it's limit. As you have said even with bad reviews, it's not necessary that you don't purchase their services, but how would you feel if someone with similar thoughts did the very same to your topic?
In fact, it's the first post that would state "Your deals are fake, scam, 1Gbps true Unlimited don't exist!". This is what I meant by jeopardizing. Instead, you could simply ask the following, "As far as I know, 1Gbps with unlimited bandwidth is quite impossible. Is your servers truly 1Gbps Unlimited?". Imagine, just that very statement could provide help to users, questioning and finding out if that is even possible.
Now, that's what I meant by making users to do their research. If they are reluctant, then that's their problem. As the saying goes, once bitten twice shy. Even with users feedback and comments, it could be fake, self-posted or unreliable.
This is a warez discussion forum, so I do understand what I suggested "might" not be suitable. Just my 2 cents.