Telecoms engineers have told Radio 1 Newsbeat they're being threatened and harassed by people who believe they're working on 5G, which has been wrongly linked to coronavirus.
Claims about any link have been branded complete rubbish by scientists.
But the union and trade body representing thousands of workers across the UK say they've had around 120 cases of abuse reported to them.
"We've actually had cases where people have been threatened with being stabbed, threatened with physical violence and in some cases actually threatened with murder," says Andy Kerr, deputy general secretary of the Communication Workers Union (CWU).
CWU represents nearly 40,000 telecoms engineers.
Andy says most aren't even working on 5G - they're maintaining the network and playing "a crucial role".
The National Crime Agency has confirmed there has been a series of recent arson attacks and cases of criminal damage to telecommunication masts.
Newsbeat's spoken to three engineers who asked for only their first names to be used because they're scared for their safety.
Olga Robinson is the BBC's specialist in coronavirus and 5G conspiracy theories.
"Scientists say 5G and the coronavirus are completely different things - as different as chalk and cheese - so you can't get the virus by using 5G.
"They also say 5G can't impact your immune system and make you more susceptible because the radio waves being used aren't strong enough to damage your cells, body or immune system."
And Olga has a few easy tips on how to check what you're reading is true.
"First of all stop and think, don't immediately share," says Olga.
"Then check the source of that claim. Who is that person, who is that group that you've seen making the claim?"