What people need to do is understandboundaries. We are at a convention, which is in public. Common sense states you don't jump on people. There are those with touching issues, and I hear con horror stories every now and then from people absolutely scared stiff when someone just jumped onto them.
Just because we're all being a little outside of societal norm, running around in cosplay, does not mean we get to toss common sense out the window. Ask permission. I don't want to have to explain to people that I know my badge sticker says NONONO, but its okay right now. Or that my badge sticker says its fine, but I'm really not in a good mood and will probably retaliate in violence if you tackle me. What if one day, I was wearing a super delicate costume, and the next I was in something very sturdy? I thought it would be fine, glomps, but suddenly my body is aching really bad? Don't forget people that simply take glomps too far, and actually cause harm.