I was called a scab once when I crossed the line of striking postal staff back in the mid 90s.
I was a chef so when they mentioned I'd be on £10 an hour I gratefully took the opportunity as there was no minimum wage at the time and I'd been working 90 hour weeks for £90 after tax. Catering doesn't have unions...
Crossing the line some hyped up t*** spat at me and shouted abuse such as scab.
It was my one day off in the week and I was happy enough to walk into thier postal office for a 10 hour night shift and earn in one night what I'd earn in a week so I shook his hand and told him to strike as much as he wanted as I'd be there as often as possible and explained why.
Don't be a cronut chap. No-one abides a cronut. People have a reason for crossing that line that you don't know about.