In light of last year's tragedy at Meron in which 45 people were killed on Lag B'Omer, among the changes for this year's festivities, entry will only be permitted to those carrying tickets. Tickets are meant to stagger the numbers of participants so there won't be too many at any one given time, with entry permitted for up to 4 hours. When purchasing a ticket, the ticket will be for a specific time. 

I guess it was bound to happen. With tickets limited, whether by number or by time, someone was going to forge them. I assume there will also be scalping at some point, if there isn't already. Some people probably bought large amounts of tickets, ostensibly for groups, and will resell them at a higher price.

Interestingly, one of the men arrested, a 19 year old Haredi from Jerusalem, is being defended by a lawyer who has claimed that he did not do it. His argument is that this young man has no knowledge of computers and only holds a kosher phone, so there is no way he could have done this. The phones confiscated during the arrest have no connection to the Internet and with his lack of knowledge in how to use a computer, it is an unreasonable suspicion to think that this young man is unreasonable for the forgery.

source: Behadrei

I dont know that any of this need necessarily be an impediment to forging documents and selling them (his partner could have done that part of it while he handled other aspects of the plan), but I obviously dont know that he did. The police will have to make their case.