This is hardly news, nor is it specific to Apple, but here we go.
The iPhone uses liquid sensors that, whenever they’re exposed to liquid, notify a service technician that the device has been exposed to liquid. This is generally a good idea, that reduces warranty fraud.
However, independent studies appear to have shown that these sensors sometimes produce false positives, while in the normal operating conditions for the phone. Obviously, this could cause major issues for owners of devices that have failed, after a false positive.
A class action lawsuit against Apple has been filed.
Source: CNET