Then how do you counter high profile WTS presence and misinformation?
They could just do exactly what the JWs are doing-- set up a sign and cart right next to them with their own literature and allow people to browse/approach/ask questions.
All that loudspeaker stuff just makes them look a little looney to everyone else on the street. It may prevent people from approaching the JW cart, but it reinforces the JW's persecution complex more than anything else could, aside from arrest or a mob beating.