Nokia says that the chargers should not be used. There are 30,000 units worldwide that are covered by the warning, including 600 in the U.S. The problem with the charger, which is made by a third party manufacturer, is that the plastic cover could come loose. If the cover comes loose, it would expose wires that could pose a shock hazard while the charger is plugged in. Nokia says that all other plugs for the tablet are safe to use.
So far, there have been no consumer injuries related to the charger. Meanwhile, some Apple iPhone and Apple iPad users have been zapped by shocks that in most cases, have been traced back to the use of a low cost third party charger.
source: Nokia via TheVerge, BGR