I've been recently reading about the A/C (Westinghouse) vs D/C (Edison) wars of 1888. As usual it was a bitter struggle over which technology was better with D/C being the incumbent and A/C being the new upstart.
Now we've seen lots of FUD (fear, uncertainty and doubt) about the open source world, sometimes subtle and sometimes blatant. Back then subtle was not part of the vocabulary.
Electrocuting people's pets (apparently often stolen) to provide evidence that A/C was dangerous. FUD on an unprecedented level with the mass circulation of leaflets making deadly claims about A/C. Newspaper articles demanding that A/C was outlawed.