Blackmail

Blackmail was a crime involving threats to reveal information to the public or legal authorities unless given payment. Sean Harris tried to blackmail Ed Morgan after he saw him murder Lizzie Lewis using a quantum transducer. Morgan refused payment and assumed Owen Harper was also after money when he told Morgan he also knew. (TW: Ghost Machine)

Using Lois Habiba's secret filming as leverage, Torchwood Three blackmailed the government to give them access to Thames House. (TW: Children of Earth: Day Four)