My first post, but a very serious subject if suspicions substantiate.
Last night the b24 exchange got hacked, API abuse obviously. Someone bought large amounts of btc at ridiculously high prices under the wrong name (while selling their own Bitcoins). Afterwards, they sold lots of btc very cheap abusing other's accounts (while buying cheap btc under their own name). This repeated several times until the admin noticed the fraudulent activities and stopped all trading. The site is down at the moment. Look at the strange chart pattern:
http://bitcoincharts.com/charts/btc24EUR#rg2zig1-minztgSzm1g10zm2g25zvNow Intersango shows a similar pattern:
http://bitcoincharts.com/charts/intrsngEUR#rg2zig1-minztgSzm1g10zm2g25zvIs Intersango going to be closed in a few hours?