This year's headlines have been dominated by one topic: spying.

Top spooks Ian Fletcher and Warren Tucker made history by appearing in front of a public hearing of the intelligence and security committee.

They offered reassurances that the Security Intelligence Service and Government Communications Security Bureau are not conducting unlawful surveillance on Kiwis.

The meeting was designed to boost public trust in the intelligence community following a series of scandals.

But many questions remain about the Kim Dotcom case and the GCSB's relationship with the US National Security Agency, through the shadowy Five Eyes intelligence alliance.

IS THE US SPYING ON NEW ZEALANDERS?

The Five Eyes 'gentleman's agreement' dictates no spying on each other's citizens. Before the committee this week Fletcher said he had no reason to believe the NSA targets Kiwis. However, he could not guarantee their electronic information was not being monitored if it passes through the United States, or other countries.

According to documents leaked by fugitive whistleblower Edward Snowden, the NSA uses PRISM to access the content of emails, video chats, photographs and other communications. The US says it accesses those online records for a "foreign intelligence purpose" and on targets outside of the US. The Snowden documents have indicated the agency has snooped on the citizens of its allies and friends.

WHAT ABOUT THE SHARING OF INTELLIGENCE?

Fletcher insists the GCSB does not flout the law by getting data from overseas agencies that it can't legally intercept itself. It emerged last week that in 2008, Australian spies offered to share raw metadata on its citizens with other Five Eyes partners. They believed they could get around the law by collecting raw metadata in bulk so that it appeared unintentional because no-one was specifically targeted. Fletcher says this meeting was just a ''conversation" about what information could legally be pooled.

IS NEW ZEALAND SPYING ON ITS PACIFIC NEIGHBOURS?

Prime Minister John Key has repeatedly refused to answer. He faced some awkward questions after it emerged Australia had snooped on Indonesia. In fact a secret document written in 1986, and released a decade later, revealed New Zealand was using Tangimoana, with the help of the US, to spy on France, China, Japan and a number of Pacific Island countries like Tonga and Fiji. Should any more recent cases emerge in the leaked documents, diplomatic relations will be very strained, particularly if the surveillance is linked to US attempts to contain China's influence in the region.

DOES NEW ZEALAND USE PRISM OR XKEYSCORE?

Fletcher wouldn't answer that question. According to the Snowden documents, XKeyscore retrieves metadata the NSA has already collected either using diplomatic posts, satellites or by tapping cables, and allows anomalies or patterns to be identified. Among the facilities listed as being involved in the programme is Waihopai Station. Commentators have suggested beefed up spying laws introduced this year allow for greater use of mass surveillance in the future.

DID THE NSA SPY ON KIM DOTCOM?

He certainly believes so, saying that he plans to offer proof the agency carried out surveillance on him, millions of Kiwis, and that it has access to X-Keyscore, in the course of his extradition court battles. Recently released police files show the GCSB was passed information from somewhere relating to Operation Debut, the raid on Dotcom's home. Most watchers are assuming it was the NSA but no further details have been made public. Again, neither Key or Fletcher will confirm specifics about operations or techniques.

WHAT DID HELEN CLARK KNOW?

Key has taken much of the flack for the behaviour of New Zealand's spies. But a good deal of the illegal spying went on under the previous Labour administration, as revealed in details of the April 2008 Five Eyes meeting. Labour is still pressing for an inquiry - saying there can't be two sets of rules.