Filter out nonsensical "+1" responses
The general population does not seem to comprehend that "+1" responses serve no purpose other than annoying everyone who is watching the ticket, especially when no one is even assigned to the ticket.
I realize your gut reaction would be to say 'this is an arms race' and close the ticket. However, I would be very sad if programmers wouldn't learn after some 'education'
Maybe put a big "+1" button where the "What do you want to say" comment box is and require a link to show the text box