Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- If you can identify anyone of those people, you can restore him what you have taken from him.
2- If not, you can just make istighfar and pay charity (sadaqah) as much as you can.
Responding to your question, Prof. Dr. Monzer Kahf, Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
These are rights of people and let us remember that as Allah Almighty kept your secret all these days do not let it be known now.
First, do whatever you can in case that you can identify those individuals, send them gifts or drop money to their places. As for those you cannot identify, try to compensate for them by giving sadaqah to the poor and the needy and pray to Allah to make the reward reach them. Allah Almighty will deliver it on your behalf, insha’ Allah. In addition to all this, try to make sincere istighfar and do not let anybody know about it.
Allah Almighty knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.