My 2008 Tacoma 4x4 looks like the rear suspension/frame area was painted black. Why is that?

I don't have a pic right now, but I'll try and get one. The rear suspension (leaf springs and associated hardware) and frame area around the rear suspension in the wheel well looks like it's been sprayed with black paint. Could this be related to a TSB?

 

there is a recall on the frames for rot. if your frame wasn't rotting they coated it to prevent it from rotting. atleast that's what they did to mine last year. it should be the whole frame not just the rear.

 

or the previous owner just took really good care of the truck and repainted everything to keep it shiny and rust free