Trolling is a concept usually involving attempting to get some entity to do something that is not in its own best interest.

Well-known examples:

• An Internet troll makes comments designed to induce angry comments. For more detail, please see Troll (disambiguation).

• Trolling for fish involves dragging a lure in front of a fish to entice it to bite.

Trolling can also mean walking. This is more or less basic slang now (from stroll), but it used to be polari.