Everyone has to decide for themselves what risks they are willing to take but I would point out that outright confiscation has happened recently.
Venezuela to offer Russians Crystallex gold project
Thu Nov 6, 2008
http://www.reuters.com/article/marketsNews/idUSN0631327220081106
The most likely model though would be to attach royalties, environmental fees or other taxes to the point where the government becomes more like a parasite. Sucking aff most of the profit from the top but leaving enough for the company to survive.
Most people are invested in gold because they see more economic problems on the horizon. In an environment where gold is rising and other government revenues are falling the mining companies will not go unnoticed.
As an investor I dont want to make the right call on gold but still not make any money because the company I invested in has a big target on it.