Is there a limit to "greater" or does it increase every time there's an incident?
You tell me. If some piece of shit threw the odd egg at my house I'd probably look out the window more often. If they kept lopping rocks through the windows I'd put in CCTV and wait to catch them.
Let's say you have 20 more mass shooting and bombings by proclaimed IS loyalists - in the next year - would you submit to more background checks on guns?
(It is probably pointless given someone not under suspicion could buy them and give them to a terrorist no problem)