A data carrier (2) comprises a data circuit (4) arranged on a substrate (3) and data transmission unit (10) being connected to the data circuit (4). The data carrier (2) further comprises at least one strain gauge unit (7) being adapted to measure strains exerted on the substrate (3) and to transmit a deactivating signal (DE) to the data circuit (4) if the measured strains exceed a defined deactivating strain threshold. If the data circuit (4) receives the deactivating signal (DE), the data circuit (4) interrupts a data exchange with an external data reader/writer (1) via the data transmission unit (10).