A physical activity assessment system (PAAS), a method, and a computer program product may be provided to detect faulty physical activity (PA) data for claiming a reward. The PAAS may include a memory configured to store computer program code and a processor configured to execute the computer program code to obtain first PA data of a first wearable device associated with a first user. The first wearable device may be linked to a first user device registered with the PAAS by the first user as an owner. The first user may claim for a reward based on the first PA data. The processor may be configured to detect whether the first PA data is faulty PA data generated by the first wearable device worn by a non-owner of the first wearable device, based on fraud detection criteria.
