I'm not sure if providing a link to content is legal or illegal, but the problem is the "hassle factor" of doing so even IF it is legal.
"Legal" generally means you can do it without being fined or prosecuted. But the "hassle factor" I'm thinking of is the civil lawsuit you might get from the content owners.
Usually they just ask your host to take your site down, and the host comes to you and either suspends your account or asks you to remove the content. If you're a small website, that's usually all they will do. But if they decide to "make an example of you", they could sue you for whatever outrageous damages their lawyers can dream up. And you have to defend against that suit, or have a default judgement entered against you.
So that's the risk calculation, in my view. Legal, yeah probably the FBI isn't going to break down your door for linking to content. But a civil case can be just as much hassle.