Google News Search with Articles. The question remains as to what made the Swiss and Italian governments nervous about Indymedia and what they thought was important enough to get a subponea.

One of the stories suggests this:

According to AFP, the federal prosecutor of Bologna, Marina Plazzi, has stated that she is investigating Indymedia because "it may support terrorism"; while the Swiss investigation dates back to the 2003 G8 summit in Evian, where the organisation posted photographs where Swiss intelligence agents could be identified.

"Mud and poison"

The Milan-based Corriere della Sera suggests that the Italian request comes as a result of the Indymedia Italia site appearing to support insurgents involved in the deaths of Italian carabinieri in Al-Nasiriyah, southern Iraq, leading to National Party demands for the site's closure.
How true that is I don't know but it would be hard for RackSpace to deny a legal request and the US is already determined to track down "insurgents" so it's no surprise that they followed through on the subponea.