Doug Leland from Microsoft has reported an increase of insider attacks on companies since the start of the economic downturn and warns that "there's an increased risk and exposure to these attacks"
The article at the BBC states that, according to a Verizon Report 18% of breaches are due to insiders, although the cost of the breaches was greater than those performed by others.
I am a little suprised by the 18% figure however, the report is based on reported breaches; it is entirely possible that smaller insider actioned breaches go undetected.