The following will take place for adding a someone eles's prospect once the season has begun.
First offense: 13th round pick will be dropped to last pick in round.
Second offense: 10th round pick will be dropped to last in round.
Third offense: 5th round pick will be dropped to last in round.
Fourth offense: Potential removal from league.
If for example a team has previously traded their 13th and as such does not then possess their own 13th round pick, the next closest pick rounding up will be the altered pick(ie no 13th then your 12th will be altered etc).
Should multiple teams be fined in the same round, the team who last violates will be the last pick meaning all other teams are bumped up(ie 16th pick then moves to 15th etc.)