What is the weakest brick?

I'm curious, could you elaborate on the metaphor 'What is the weakest brick?' in the context of cryptocurrency and finance? Are you referring to a specific vulnerability or weakness within the system that could potentially be exploited? Or is it a broader question about identifying the most susceptible aspect of the industry to potential risks and challenges? Understanding this concept is crucial for investors and practitioners alike to ensure the stability and security of their investments and operations within this rapidly evolving field.