What sort of questions should a parliamentary inquiry into media ownership and regulation tackle? Wendy Bacon has a few ideas - and we invite you to add your own.

Last week Greens leader Bob Brown called for a parliamentary inquiry into media ownership and regulation. His concerns were triggered by the wave of revelations about the conduct of News of the World journalists in the UK. The briefing paper issued by the Greens lays out their concerns and has been published here.

Last night, Rupert Murdoch, James Murdoch and Rebekah Brooks faced questions from British MPs about their conduct through the phone hacking scandal. This mode of questioning isn't quite what the Greens have in mind, but the transcripts show that MPs were anything but deferential to the media bosses.

Peter Costello argues in the Fairfax opinion pages today that we don't need a media inquiry at all. His view is that an inquiry would actually work to stifle free media. Of how Julia Gillard and Stephen Conroy would approach an inquiry, he writes, "they are smart enough to know that if an inquiry opens up ownership and regulation issues, they can promise benefits or withdraw privileges that may have a real financial effect on publishers. And with an inquiry under way, owners and their editors might be a little more careful about their criticism."

Costello may be resting on his own experience of media inquiries in Australia — see NM's timeline here — but the forensic questioning of Rupert Murdoch has surely changed how any such inquiries will be conducted in the future.

Yesterday, Wendy Bacon argued that the time is ripe for Australians to pressure politicians to respond to public concern about the concentration of media ownership and its effects. Today, she gets the ball rolling with a series of questions that such a committee should investigate.

What's missing? What should a parliamentary inquiry into Australian media investigate? Add your ideas in the comments.

Is there too much media concentration in Australia and if so, how can it be corrected?

How do criminal activities which in the UK have gone to the heart of News Corporation media practice impact on the "suitability" (this word replaced "fit and proper" in Australian legislation in 1991) of companies partly owned by News corporation to hold radio and TV licences?

Should News Ltd close one or more newspapers in Australia without there being a buyer what steps can be taken to protect access to media by Australians?

How should press council or some other body be funded to strengthen its independence so it can take on ownership — systematic abuses as well as individual complaints?

What problems for media diversity and practices are raised by media owners who also have interests in mining, sport and casinos?

Has News Ltd's practice of sharing information and stories across the company meant that their Australian tabloid audiences have been exposed to stories resulting from hacking and bribes?

Australia's latest media ownership laws have led to more not less concentration — should they be further revised?

Do News Ltd editors respect the professional independece of their journalists or do they compaign to impose certain views or political lines on their journalists to the detriment of the public — e.g. in relation to climate change?

What policies can be adopted to support diversity in rural, regional and smaller capitals of Australia where there is high concentration and limited media outlets?

How much do new internet ventures and small magazines compensate for the concentration in the mainstream media?

How can methods of accountability be developed which do not threaten the right to freedom of expression?

What forms might regulation take — should it be cross media? How can the dangers of statutory intervention be avoided? Would a publicly funded but independent regulator which is not dominated by current media companies be preferable to the current Press Council and ACMA self-regulation?

How should media owners and politicians relate to each other, if at all?

How could editorial charters of independence help ensure that journalists report the truth and not the company line?