Theres a bug in survival, and possibly factions too, where you can break minecarts In factions that you aren't allied with, don't have access to, or are a member of, and it doesn't matter if it is a normal minecart, hopper, chest or even tnt cart, it can be broken in other factions' land. Here's a little video I made of the bug (I used the carts in @~Wolf's faction, don't worry, they're still there): Im not sure if this is actually a bug nor if it can be fixed, but if some factions have chest carts that have items inside, any outsider can break them and steal from them. EDIT: You can also Place TNT Carts, they explode, but at least they don't do any damage other than a small fps lag spike.
Just tested it in factions, and it does nearly the same thing, but it works with tnt carts, which can be used as an exploit for raiding bases. you could simply put a tnt cart on minecart tracks in enemy land. Proof:
