I've done similar things in a coffee shop before, just working on my own code, and I have actually been 'politely' asked to leave by the staff.

The staff evidently being a bunch of morons who thought I was... hacking into ... something?

They didn't know what, but they were very concerned.

I was unable to convince them I was not, because 'terminal' = 'hacking' to idiots who only know anything about computers via movies and tv shows.