Realising that a former partner had, unbeknownst to him, put previously private, intimate videos of them onto a porn site, tech founder Dan Purcell felt devastated. He resolved to come up with a solution to help prevent such violations happening again. His Ceartas startup has now raised $4.5 million in a Seed round from European VC Earlybird, as well as Upside VC, a fund established by…