The biggest difference between insider and external threats is that while businesses are often equipped to deal with the latter, they tend to be left wanting when it comes to monitoring and detecting unusual or suspicious employee behaviour. In a recent poll of 300 IT decision-makers, Clearswift found that 83 per cent had experienced a data security incident in the past year. 58 per cent of these respondents believed an insider was the culprit, while seven per cent laid the blame at the door of former employees.”]
Source: https://informationsecuritybuzz.com/news/an-inside-job-the-danger-that-lurks-within/