Online services and exchanges dealing in Bitcoins have been hit by hack attacks that led to a drop in the value of the virtual currency. Trading on the MTGox exchange, which handles most trades in Bitcoins, was sluggish yesterday as the site fought off an attack. The attack helped to force a swift fall in the price of Bitcoins. In addition, the Instawallet website - where people store Bitcoins - is offline indefinitely after an attack. Website bombarded The value of Bitcoins surged to a new high this week with each one worth about $142 (£94). Barely a week ago, each virtual coin was worth only $90. But Bitcoins ... (full story)