Reebok has started the Whodunit? campaign in Europe. What's important to notice is that they're running it exclusively online. As explained on Brand Republic Flash video ads will play a key role in the campaign, with the goal of raising Reebok's brand awareness and drive response.
The banner are currently performing on Yahoo! and Msn networks. Here's a screenshot of a floating ad I've found today on Yahoo! inside the "Sport" section.

Read more on the Whodunit? campaign in the US.