I think it all depends how the link is used. If it is a public domain website used as a reference. If using to promote or advertise something on a social media site you have to read the fine print what you can and cannot do. Hope that helps a little. Also I found this when I googled.

I"n general, by including a hyperlink, you are not actually copying. It is generally fine to provide a hyperlink to another website as long as that link is not a site which is known to contain infringing material. The law is not clear on deep linking."

Hope that helps some.