The proposed Foreign Fighters Bill is written in such a way as to catch all of us and strip us of our civil liberties. After all, we all have something to hide, writes David Leyonhjelm.

If Nick O'Brien was still at New Scotland Yard in 2006, he would presumably have heard the Pet Shop Boys song Integral, in which they launched a blistering attack on the Blair government and its extraordinary plans for DNA data retention and national identity cards.

I mention this because Mr O'Brien's confident assertion in The Drum last week that "most people will not be affected by this, (the Foreign Fighters Bill)" is eerily reminiscent of Integral's lyrics:

If you've done nothing wrong, you've got nothing to fear If you've something to hide, you shouldn't even be here.

The Abbott Government's Foreign Fighters Bill is all about isolating the (mainly Muslim) baddies from "Team Australia". However, even if all Muslims were as bad as some seem to think they are, the bill is written in such a way as to catch all of us and strip us of our civil liberties.

Mr O'Brien forgets that all of us have something to hide, at least some of the time. Whether you're a lonely bloke looking for porn, a rural woman chasing down an abortion, or even someone who's just bought their nearest and dearest a gift online cheaply but wants him or her to think you paid a fortune for it, there's something you don't want to reveal.

This whole "national security" and "foreign fighters" fuss is predicated on a confusion of several questions, all of which need to be kept separate.

First, there is the extent to which Islamic State activities in Syria and Iraq genuinely threaten Australia. We have seen repeated assertions that they do - including in the enormous Explanatory Memorandum to the Foreign Fighters Bill - but no evidence to that effect.

I'm sure I'm not alone in wanting to see credible examples of harmful activities that only the passage of this bill will discourage, even if identifying details are redacted for security reasons.

Second, there is the extent to which Muslims are able to integrate into Australian society. Those of us who reject the growing surveillance intrusiveness of Australia's law enforcement and intelligence agencies should not pretend that integration isn't an issue.

Even if only at the margins, there are serious cultural differences that - due to the desire not to appear racist, in part thanks to section 18C - are not being addressed candidly. However, Islam is a religion, not a race. If people feel they cannot leave it behind - as one cannot abandon one's race - there are grounds for legitimate criticism of Islamic doctrines such as its policy towards apostasy.

Third, there is the need - if we are to address both the above issues - to ensure that we keep channels of communication open. Tony Abbott wants to use passage of the Foreign Fighters Bill to ban Hizb ut-Tahrir based on the new offence of "advocating terrorism", but this is barmy. I would much rather Hizb ut-Tahrir be legal so that its obnoxious spokesmen can continue to appear on Lateline and reveal that they are deeply uncomfortable when asked questions by women who refuse to demonstrate doormat-like behaviour.

Forewarned is forearmed.

Precisely because the Attorney-General persists in rejecting my arguments for sunset clauses - which Mr O'Brien concedes - this law will remain on the books far longer than the Abbott Government will remain in office, inviting abuse and "mission creep" by future regimes of every stripe.

In the 1950s and '60s, we had a "Reds under the bed" scare. Now we're having a "Muzzies under the bed" scare. In 10 years' time, there will no doubt be someone else (allegedly) under the bed about which our security services can whip up hysteria.

And what security services they are.

Remember that AFP raid, conducted in the full glare of media publicity, a few weeks ago? A bunch of IS supporters in Western Sydney were going to blow up Parliament House and behead a random bystander, we were told.

Well, only one person has been charged (everyone else was released on their own recognisance), and the sword wrapped in an AFP evidence baggie and featured on telly screens across the nation was reportedly made of plastic.

And the people arrested were Shiites.

Islamic State is rather fond of butchering Shiites in Iraq and Syria. The likelihood of Shiites anywhere in the world supporting it is negligible to nil. The AFP (or KFP, for "Keystone Federal Police") managed to generate the law enforcement equivalent of not being able to tell the difference between Protestants and Catholics in Northern Ireland.

In 1951 Australians, to their credit, voted at the polls not to ban the far more dangerous (and far more intelligently organised) Communist Party. We can do better than provide glib assurances to people that if they've done nothing wrong, they've got nothing to fear.

Instead, we can debate like grown-ups, be honest about how much Australia is threatened, and reject setting our intelligence services on the Australian people.

David Leyonhjelm is the Liberal Democrat Senator for NSW. View his full profile here.