'Terrorism suspect' in (formerly Great)Britain: someone buying a tool

If you see something suspicious, like someone buying knives, hammers and other objects that could be used to cause harm - ACT.

Reporting it won't ruin lives, but it might save them
"Comrades, be a good citizen!  Inform on your friends and people on the street!"

And that 'won't ruin lives' crap?  Asshats, you're putting people in jail for saying something you don't like on social media, and you expect people to believe that reporting someone as a possible terrorist won't cause problems?
"I saw this man buying a big knife/hammer/pruning tool with sharp edge, he might be up to something!"  "This woman was buying chemicals, she may be building a bomb!"  Oh yeah, that'll work.  Not to mention the possibilities for, say, a bitter ex or disgruntled coworker to screw you.

I fear it's past the 'spinning in their graves' point, a lot of old Brits are trying to move their coffin to somewhere else.  Because they're ashamed of what Britain has become.