The Freedom of Expression Institute have produced a very useful copyleft guide to organising legal marches and to responding to illegal police action and illegal bans by City Managers and others. It is availabe here on this site and here at the FXI site in pdf.

It's quite instructive to contrast the law, as it is carefully elaborated in the FXI handbook, with the reality of what has actually happened to Abahlali baseMjondolo protests. Click here to see The Police and Abahlali baseMjondolo.