The CFL took a step perhaps without precedent in the league's history Monday, with commissioner Mark Cohon issuing a statement that former Baltimore Ravens' running back Ray Rice would not be allowed to play north of the border. Rice was cut by the Ravens and put under indefinite suspension by the NFL Monday following TMZ's release of video footage of the domestic violence incident he was involved with in February. However, while NFL suspensions have been upheld by the CFL while the player is still under contract with an NFL team (the infamous "Ricky Williams Rule", which is what's currently keeping Josh Gordon out of football), the league clarified in late August that CFL teams are typically permitted to sign players suspended by the NFL, but without contracts with NFL teams. Toronto Argonauts' receiver LaVon Brazill is in that situation right now; the NFL suspended him, the Colts cut him, and the Argonauts signed him. It seems unlikely any CFL team would have followed suit and signed Rice given how toxic he is right now, but Cohon's decision to change the league rules and specifically ban Rice from playing north of the border is still incredibly unusual. It's also very smart.
Going back to the CFL's official formation in 1958, it doesn't appear the league has ever formally banned a player league-wide. There have been plenty of players who have gotten into serious trouble off the field, been released and never played another down in the Canadian game, including Trevis Smith (who was sentenced to five and a half years in jail for knowingly exposing women to HIV), Adam Braidwood (currently in jail for offences ranging from sexual assualt to forcible confinement) and Yonus Davis (who just got out of jail for his involvement in a drug scheme that saw him caught with 67 pounds of ecstasy and wants to try the CFL again, but isn't finding many takers). Even Arland Bruce III (who's currently suing the league over concussions) might have a case that he's been unofficially banned; he recorded 851 receiving yards last season, but hasn't found a landing place since Montreal released him following his homophobic Instagram comments. (That also might have something to do with his age and colourful history, though.) However, there have been no reports of any of those players being officially banned from the CFL, and about the only thing that even has been reported as potentially triggering a lifetime ban is a fourth violation of the league's drug policy (which has never happened). Each team usuallly makes its own decisions on discipline, and that approach usually works.
In the case of Rice, though, this seems like a smart and proactive move from the league office, even if it is taking some criticism as inconsistent. Rice's actions, the NFL's initially-light two game suspension for them, and the release of this video in particular have created a firestorm of such magnitude that even attempting to sign him would create an incredible backlash. Yes, Rice has been one of the NFL's best running backs over the last few years, and his mix of rushing and receiving ability would absolutely land him on a CFL roster if off-field issues weren't a consideration. (That would only matter if he wanted the job, though; not everyone who was on a 5-year, $35 million NFL contract would want to go make $100,000 to $200,000 at best in the CFL, even if he's not owed any further money by the Ravens.) Off-field issues very much are a consideration here, though, and signing Rice (or even adding him to a negotiation list) would spur huge protests against the team involved and the CFL in general. It would look awful for a league that has teams trying to be leaders against domestic violence to go after a player as controversial as Rice.
From this corner, Cohon's decision to ban Rice from the league is a logical move. It shouldn't be seen as a precedent-setting decision or a move to be in lockstep with the NFL's disciplinary policies, though, as the latter approach in particular would be problematic. Generally, issuing disciplinary rulings based on a specific player's case is a bad idea; it opens the door to all kinds of criticism for inconsistency (which the CFL won't be immune from here given the league's current employment of Chad Johnson), and that's been such a huge part of why the NFL's discipline has been under fire. However, the Rice case (and in the public furor it's created) is clearly outside the norm, and it demands unconventional action. The downside of Rice even being considered by a CFL team would outweigh the upside so significantly and have such negative implications for the league as a whole that it had to be nipped in the bud, and that makes the commissioner's decision to make an unprecdented move here not only justifiable, but praiseworthy.