This paper contains, firstly, an approach of the banking liability from
electronic frauds committed against their clients, under both the fault
liability and strict liability regimes. Following this topic, there is an efficiency
analysis of the same issues with microeconomic tools. With those basis, in the first part there is only a legal analysis, focused in the Colombian law and some proposals of different authors from the benefit risk, created risk and professional risk theories; the second part begins with a brief description of the Colombian financial market and its agents, and concludes with the efficiency analysis under the Pareto and Kaldor-Hicks criteria. The author concludes that the strict liability is not possible in the case analyzed, under the Colombian law, and it is not either an efficient option.