The state of Minnesota recently legalized the practice of scalping tickets. The Missouri Legislature is considering lifting a similar scalping ban in that state as part of an overall "economic development" bill. The bill is supported by all of Missouri's major sports teams.
Skip Sauer at The Sports Economist writes:
The internet obviously made it much easier for buyers and sellers to exchange tickets to sporting events, and I'm all for loosening the restrictions on secondary markets. It should surprise no one that former opponents of scalping (the sports franchises) are now in favor, given that they can get a piece of the action. As has been pointed out here before, resale demand increases the value of the initial sale as well. Thus the franchise can win on both ends, particularly by earning a return from offering a safe and secure exchange mechanism. The only losers are the ticket touts operating under the corner lamp post. Long live ticket scalping!
Historically, teams have had to deal with some of the consequences of ticket scalping, such as dealing with counterfeit tickets, losing control over who can obtain tickets to games, and having to deal with pushy scalpers outside of stadiums and arenas (see here). But until the internet made it possible for teams to get in on the action, they didn't receive any of the benefits. Now they can. So it's understandable why they supported scalping bans historically and why they have changed their tune recently.