Wiktionary
act on
vb. 1 To act decisively on the basis of information received or deduced. 2 To take action against something. 3 (context medicine English) To affect something.
WordNet
act on
v. carry further or advance; "Can you act on this matter soon?" [syn: pursue, follow up on]
regulate one's behavior in accordance with certain information, ideas, or advice; "The Founding Fathers acted on certain moral principles"
Usage examples of "act on".
His reputation is such that they would be forced to listen to him and, however reluctantly, act on his accusations.
From what I hear, the Blood doesn't bother with questions, they simply act on rumor, as long as it results in a fresh grave.