Some patients from the Vastaamo psychotherapy centre had died by suicide after their patient records were stolen and used in extortion attempts, according to a lawyer representing victims.
Legal arguments in the trial of Aleksanteri Kivimäki, who is accused of stealing the data and extorting victims, are scheduled to conclude next week.
Lawyer Jenni Raiskio said in her concluding statements that her firm had been contacted by people whose relatives had taken their own lives after the patient records were published online.
She said that others had told her they had considered suicide after the leak of patient data.
She then called for a moment of silence for the victims.
Raiskio's firm represents some 1,500 victims in the case. Around 33,000 people's patient data was stolen and published online.
Prosecutors argue that Kivimäki stole the patient records in 2018 before starting to extort victims in 2020. They say he then published part of the information, before accidentally publishing all of it.
Prosecutors are demanding Kivimäki be given a seven year jail sentence over the crimes, the maximum possible penalty.
He denies all charges. The defence case is expected to conclude on 8 March.