Linq Orderby random ThreadSafe for use in ASP.NET

i'm using Asp.net MVC with Sharp Architecture.

I have this code:

return _repositoryKeyWord.FindAll(x => x.Category.Id == idCAtegory)
                .Take(50).ToList();

How can i order by random? Note: i don't want to order the 50 extracted items, i want order before and then extract 50 items.

thks