well, maybe in the case of a newborn screaming baby:
put them on the phone;
they will then screech out the phone number for an ISP;
upon hearing the tone, will initiate a V.92 handshake;
it will then remotely log into the system via SSH, and transmit,
compile, and execute, a program.
this is because the human brain just so happens to be compatible with
dial-up modem technology.
cats are similar, except they will use pulse-code dialing. or, at least,
when not directly typing on the keyboard, which can have effects
anywhere from sending people to/from cyberspace (by them flying
into/out-of a CRT display), to infiltrating remote government systems,
to making potentially covert changes to ones' source code. most results
are annoying though, but it is hard to keep cats off the keyboard...
vegetables, however, require either the use of fiber optic connections
(for green leafy plants, given that they are optically-based), or metal
probes in the case of potatoes (however, this experience will leave them
forever transformed, into either a large robot or sentient AI core...).
they will then be in control of nearly anything even remotely mechanical
or electronic (computers, cars, cables, power cords, levers, bicycle
person gets attacked by a ball of yarn and some knitting needles and
turned into a remote-controlled doll-robot thing (with a quilt-work head
and glowing button eyes), faithfully carrying out the will of "the head
of lettuce" (which by this point will have gained many additional fiber
optic connections, and an automated defense system).
luckily at least (for the person hoping to stand up for themselves),
nearly everything even vaguely electronic or mechanical is made out of
explosives, and so will explode violently when hit with a pipe or crowbar.
leading to a final showdown with the then human-form 15-foot-tall
lettuce mecha in an abandoned factory, with unstable cat-walks (prone to
collapse without warning) and flows of molten metal, random
flame-spewing, pipes filled with pressurized steam, and lots of smoke.
it is then defeated by being kicked into a large open-top vat of molten
metal, as the hero hangs from a chain above the vat, lucky to have won
this battle and/or saved the world.