NavList:

There is a double navigation history angle here.  The "drone" snatched by the Chinese was a "Slocum", a class of sea gliders named of course after Joshua Slocum. They are lovely little devices, so named because like their namesake, they are designed to operate autonomously for weeks at a time.  The thermal version exploits differences in the water column to power its movement, accomplished by sounding and surfacing.

Speaking personally, I think the slocums are rather cute and have personalities.  So I am inclined to consider this a kidnapping (or more preciesly, a bot-napping) and not a mere theft on the high seas.