A team of developers working at trezor have been trying to find a weakness in trezor for the past 3 years the only time anyone got close was when a developer that now works for trezor managed to find a part of the seed using an electron microscope , this issue was quickly secured with a firmware update , even then any potential thief would have had to actually have your trezor. It is impossible to ( hack ) a trezor because it is never actually connected to the internet and your private keys never leave the device. To date no one has ever lost any bitcoin or had them stolen while using a trezor.
Regards. Kr