From the FAQ:
Team Issue
Cards released by teams for giveaways. Usually no manufacturer noted.
Nothing about who paid the printing bill. Just "released by the teams" which would include at the stadiums. Police sets have always been collabrative projects between teams, local law enforcement, and usually a sponsor (the one paying the bill). The cards were released (handed out) by the teams, the players and police. Most commonly at stadiums, during public appearances (usually in schools) and at police education programs such as DARE.
Someday my cards may double in value and then be worth half of what I paid for them.