Hindenburg takes aim at Dorsey's payments firm Block, shares plunge
Hindenburg Research on Thursday disclosed short positions in Block Inc and alleged that the payments firm led by Twitter co-founder Jack Dorsey overstated its user numbers and understated its customer acquisition costs.
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### Instruction: Hindenburg takes aim at Dorsey's payments firm Block, shares plunge

### Response: Hindenburg Research on Thursday disclosed short positions in Block Inc and alleged that the payments firm led by Twitter co-founder Jack Dorsey overstated its user numbers and understated its customer acquisition costs.