19 year old lad from Glasgow went on Facebook calling some other lad secteraian stuff.
Next day cops arrested him so yes you can be. Depends if it's reported to police and once viewed they deem it needs to be investigated. Once interviewed it's passed onto the crown who ultimately make the decision whether to proceed with prosecution.
The cops can charge him if a crime is committed but again even a charge the crown has the final say.
I honestly believe some of these cases are either dropped or taken further depending on whichever crown officer reading the police report is offe