The same thing happened in apartheid South Africa but people were mobilised even more strongly as a result – going to prison if necessary. The same will happen re Israel. Criminalising protest simply gave more publicity to those standing against the human rights abuses (whites going to prison = massive media coverage). It just accelerated the fall of apartheid.
There will be many who will support BDS regardless of the cost. I, for one, would be happy to go to prison rather than give into the bullying tactics of the racist Zionist regime. It would be the least I could do given the years I spent as a Zionist ignorant of the horrors being inflicted on another people in my name.