First Great Western is offering a £5,000 reward after what is believed to be a large brick smashed through the driver's cab window of a high speed train at Taplow station (link below.)
http://www.firstgreatwestern.co.uk/NewsItem.aspx?id=435

At around 19.45 on Thursday, 8 February , the 19.15 London Paddington to Swansea service was passing through the station when the object was thrown from an overbridge. It smashed through the driver's window , showering him with glass. Although he was uninjured , the driver was unable to continue the journey and was relieved at Maidenhead. The train was taken out of service and moved to a depot at Old Oak Common near London Paddington. Passengers were detrained at Maidenhead and caught the next available service some 15 minutes later.