Crackdown Construct

• WWizards of the Coast2017-02-09
  Official Ruling
  An ability whose cost is simply can be activated as many times as you'd like. Each activation causes Crackdown Construct's ability to trigger.
• WWizards of the Coast2017-02-09
  Official Ruling
  Crackdown Construct's ability doesn't trigger if you activate an ability of an artifact or creature card not on the battlefield.
• WWizards of the Coast2017-02-09
  Official Ruling
  An activated mana ability is one that could add mana as it resolves, doesn't have a target, and isn't a loyalty ability.
• WWizards of the Coast2017-02-09
  Official Ruling
  Activated abilities are written in the form "Cost: Effect." Some keyword abilities, such as equip and crew, are activated abilities and will have colons in their reminder texts.

Rulings via Scryfall