The joint initiative puts some additional heat on internet giants like Facebook, Google and Twitter, since they know that a policy implemented in one country is more likely to show up in another.

But will it amount to much? That's not so clear. Those same tech companies have already been cooperating with officials in some ways, and there are signs they've been making significant progress in screening out hate and other extremist views. There may not be much need to push for greater action if it's really just a matter of time before anti-extremist screening gets a passing grade. Also, there are likely limits as to how far the UK and France can push: they couldn't expect Facebook to catch every single extremist post with automatic filtering. While the partnership could prompt changes, it could just as easily amount to political grandstanding.