You might have seen a Cubs fan run onto the field at Great American Ball Park after Jake Arrieta completed his second career no-hitter. He's quite visible in this video:
This is not a good idea. According to TMZSports.com, the fan was arrested:
Video captured Dylan Cressy jumping from the stands onto the field and jumping around with the team after the final out ... before a cop forcibly removed him from the celebration. Turns out, he was taken straight to jail ... where the 22-year-old was charged with criminal trespass for entering the field area without permission. Cressy is still in custody -- and is set to be arraigned this afternoon. So the question ... worth it!?!?
In response to the question asked in the TMZ quote above, I'd say "No," not ever.
But perhaps your opinion is different. That's why I've attached a poll to this article. Weigh in with your thoughts.