For an experiment that simulates miniature black holes, I think that the biggest concern in our minds would be that it had better not fall in the wrong hands.
An unnamed scientist working for the Large Hadron Collider project in Switzerland was arrested for being connected to Al-Qaeda. The arrest was made by French police at the town of Vienne earlier this week. The arrested man worked at the Hadron Collider since 2003. Supposedly the arrested man had even made suggestions on French targets.
After the arrest was made, the European Nuclear Physics Organization (CERN) stated “none of [their] research has potential for military application,” and added that the arrested suspect “had no contact with anything that could have been used for terrorism.”