NFL commissioner Roger Goodell's decision to rule the Detroit Lions guilty of tampering was based on more than some comments Gunther Cunningham made about wanting to sign players the Kansas City Chiefs dump. According to the NFL's statement on the matter, the Lions were guilty of tampering partly because of Cunningham's comments and partly because they had "impermissible contact with a player (or his agent) under contract to the Chiefs."
The player in question, according to the Free Press' Dave Birkett, is current New England Patriots safety Jarrad Page. Page was traded to the Patriots prior to the 2010 season, but he had requested a trade much earlier in the summer. The Lions were reportedly very interested in acquiring him, and apparently at some point somebody from Detroit spoke to Page, either directly or indirectly (through his agent).
Knowing that this finding was part of the NFL's decision to find the Lions guilty of tampering sheds much more light on why the punishment involved losing a draft pick and swapping another. Making general comments about players on other teams is one thing, but you have to know that the NFL will not tolerate contacting a player from another team (or his agent). Although Page was not technically under contract until right before he was traded to the Patriots, he was a restricted free agent, meaning he was not free to negotiate with other teams.
Detroit's punishment from this tampering charge will force them to wait to go on the clock in the fifth round until the 23rd pick. Originally they were set to pick ninth in the fifth round, but the Chiefs will go on the clock then. Also, by losing their seventh-round pick, the Lions are down to only five picks in the 2011 NFL Draft, all of which are in the fifth round or earlier.