In George Orwell's dystopia "Nineteen Eighty-Four", Newspeak was the corrupted/purged language everyone was supposed to speak according to the totalitarian dictatorship which ran everything. Words with subversive potential and those which had unclear meanings were eliminated, along with references to the past. The attempt was to bring language, and therefore thought, into line with the wishes of the rulers.
It is also used to refer to any instance of politically-invented language put out through apparatuses of propaganda and social control or by spindoctors.
This doesn't mean you shouldn't make up new words. Nor does it mean that every political or invented word should be suspect. The point is that new words should expand meaning, not contract it. If a word is used to cover up abuses by the powerful or to manipulate people in favour of the existing regime, it's Newspeak.
Thinking you're better than other people because you're working class, have a regional accent, don't use big words, read tabloid papers, or for other reasons which are opposite to those which would be involved in "snobbery" in the usual sense.
The argument that people who live in "rough" areas are the only ones who "know" about crime and that everyone else should shut up is just an example of inverse snobbery.