Terrorist attacks were pretty common in the 70s/80s - only it was Irish terrorism -
I have never forgotten the earthquake-like feeling when the waterpumping station in Woodford (NE London) was bombed (I was also close enough to feel the ground move for the Canary Wharf bombing as well)
The Conservative party conference was bombed as well as bombs left at McDonalds that killed children and numerous pub and car bombings at the Old Bailey, Houses of Parliament, Tower of London and army recruiting officers etc
Most public buildings were on red/amber alert so you couldn't enter without having all of your possessions examined by security - same for large shops
Pupil murders were not-common but it happened at the high school nearest my house in the 1970s
Immigration was also controversial in the 1970s - the UK accepted 20,000-30,000 Vietnamese boat people and around 40,000 Ugandan Asians expelled by Idi Amin
Plus the UK was actually at War with Argentina in the early 80s
People get whipped up into thinking this is a new issue but really it's not - I guess 24 hour news and social media rumours means it all spreads faster