While customers victim of online scams and identity theft are more or less protected by big vendors or banks because of regulations, provided they act swiftly,

While customers victim of online scams and identity theft are more or less protected by big vendors or banks because of regulations, provided they act swiftly, small merchants are often on hook when a scam happens with very little options to recoup the money lost. What are the solutions for merchants? insurances? anti-fraud detection services? What could you recommend to a merchant that is starting to do business online? restrict with whom one does business with? use bigger merchants to do transactions? what works, what doesn't to mitigate risk?