The whole idea of the Vital Things site is for it to be as free to use as possible. The point was/is to create a place on the internet that allows anybody (well, almost anybody, I'll come to that bit later) to share thoughts, ideas, art in all it's forms, to provide a virtual safe space without censorship.
Having said all that, there are obvious exceptions. So here are the Vital Things Terms of Usage.
i. DON'T BE A DICK.
That's it really. If you understand what that means, then you're doing fine.