According to AARP, this is a common scam that has cost grandparents millions of dollars. Unfortunately, the tax rules don’t help in any way. The deduction for a theft loss—assuming such scam is a theft under state law—cannot be claimed in 2018 through 2025.
Loss from an unforeseen and sudden event that is deductible, subject to a 10% income floor and $100 reduction for personal losses.