Externalism vs. Internalism

the Stanford Encyclopedia gives the best example:

"To give a trivial example, externalism is true of mosquito bites since having them requires having been bitten by a mosquito. A mark on the skin created by careful micro-surgery is not a mosquito bite, even if it is intrinsically indistinguishable from a real one." http://plato.stanford.edu/entries/content-externalism/#Int