Not just a large amount of something, but a gregarious amount of something you don't want. Similar, at least in idea, to too much.
One can't have a shit ton of money. One can, however, have a shit ton of ants in ones pants, or a shit ton of holes in a bag of money.
Upon entering my kitchen I noticed there were a shit ton of ants everywhere.
After taking my final exam, my friend and I concurred that there was a shit ton of material we did not know.
It takes a shit ton of gas to drive from California to New York and back.