This question is in response to an answer on another question. Due to my lack of reputation on this SE I couldn't comment on the answer.
Based on JonTheMon's answer to Can a continuous effect that gives haste wear off? , destroying a creature that gives Haste to an artifact creature would remove Haste from the newly summoned artifact creature. But then he goes on to say that the activated Tap ability would be allowed. How?
According to the official rules on Haste (http://mtg.wikia.com/wiki/Haste), tapping or untapping falls under the same rules as attacking.
702.10b.
If a creature has haste, it can attack even if it hasn't been controlled by
its controller continuously since his or her most recent turn began.
702.10c.
If a creature has haste, its controller can activate its activated abilities
whose cost includes the tap symbol or the untap symbol even if that creature
hasn't been controlled by that player continuously since his or her most
recent turn began.