The attacker appeared to be roughed up by some of those intervening (Dash Wilder, Harry Smith, and Travis Browne have been cited the most), before being dragged out of Barclays Center to a chorus of jeers.
According to Arash Markazi, a Los Angeles Times sports reporter, the attacker (whose name has not been released as of this writing) was apparently charged with two counts of assault in the third degree, and disorderly conduct. Markazi also posted his own footage of the aftermath of the attack.
WWE released a statement on the matter, saying, "An over-exuberant fan surpassed our security at ringside and made his way briefly into the ring. The individual has been turned over to the proper authorities."