As long as you are under the max rating for the truck you're good to go. If you're over that weight then a nice govt employee could give you a ticket.

Where I live, the max is 10K (as indicated on the trailer tag, not the actual load) with a regular license, drivers with a a class 3 license (commercial license) can tow trailers rated higher than 10K.

Anti-sway devices are also required after a certain point (either length or weight, dont remeber)