Technically it's the owners that are locking out the players, although there is bad blood on both sides of the labor negotiations litigation. So when the Green Bay Packers ask for money from season ticket holders, for games that might not be played because they've locked out the players, they are trying to have it both ways.
So far only the Giants have agreed to defer payments until such time when the players and owners agree to a new CBA. Kevin Seifert is waiting to see if any other team does the same, but so far the Giants are a lonely voice. From Arrowhead Pride:
Next, there is an official league wide policy of issuing refunds for season tickets if games are missed. Also, a number of teams' refunds include the cost of the season tickets plus, wait for it, 1% in interest! Yes, 1% interest. Many NFL teams have already notified their season ticket holders about the interest rate.
So Packer season ticket holders have that going for them. I don't have to write that check out every year, although I wish I did, but it would hurt a little knowing that all it might be doing is providing the Packers a short-term loan at a nominal interest rate.