In general, lines are there for a reason.

For security, for clarity. If you choose to cross the line, you pretty much do so at your own risk. So why is it that the bigger the line, the greater the temptation to cross it? We cant help ourselves. When we see a line we want to cross it. Maybe it’s the thrill of the unfamiliar, a sort of personal dare. The only problem is once that you’ve crossed, it’s almost impossible to go back. But, if you do manage to make it back across the line, you find safety in numbers."