It's was relatively easy and within reach of many people to do so back then. It took a bit of technical know how, don't money and you could hijack done TV signals and send out a signal that people could see.
Now it would probably take a good amount of money, lots of skill, lots of knowledge and lots of people in coordination to hack a site or service to try to reach out to a small corner of the internet. Everything is locked down now ... sure they can be bypassed and hacked ... it just takes far more effort and skill and money than it did 30 years ago.