The income-tax department is targeting top multinational corporations in the country for violation of norms regarding tax deduction at source on salaries of expatriates, department sources said here yesterday. A recent I-T survey revealed that this was done deliberately by these companies. Interestingly, several MNCs contacted by the department expressed ignorance of these norms. The department is also planning to conduct seminars to educate companies about the recent changes in TDS norms.