They're actually already doing that by really tightening the rules on things like collectibles (insurance, market valuation each year, additional documentation, blah blah).They would just make it so a fund couldn't hold an assett that can't be readily valued. Easy.
Stroke of a pen, you get 12 months or even 24 months to remove it from your fund.
It really, really annoys me, because it needlessly makes my job harder. And if my job becomes harder you can gaurantee that you guys with SMSF will be paying me more to do your tax return each year!
Sorry for ranting a bit, but I hate red tape.