Every distinct wording since 2010, newest first.
July 12, 2019 · Core Set 2020
The controller of an activated ability on the stack is the player who activated it. The controller of a triggered ability on the stack (other than a delayed triggered ability) is the player who controlled the ability’s source when it triggered, or, if it had no controller, the player who owned the ability’s source when it triggered. To determine the controller of a delayed triggered ability, see rules 603.7d–f.
February 1, 2010 · Worldwake
Some objects check what another spell or ability is targeting. Depending on the wording, these may check the current state of the targets, the state of the targets at the time they were selected, or both.