Would you return a lost wallet lying in the street?  Of course!

Researchers left 17,000 wallets in 355 cities around the world (wow! big spenders!), some containing money, small or large amounts.  They found that, when cash was found the finders tended to return it to the owners.  If the wallets contained small amounts, say £10, the rate of returns was 51%., but at £75 the rate rose to 72%.  Clearly, most people see themselves as honest, as having a conscience, and would be shocked to be regarded as thieves.  Researchers concluded that, for most people, a moral self-image is important, and that they get quiet satisfaction from being seen to do the right thing.

Supporters of Epicurus would suggest that simple things like returning lost money to its owner are part and parcel of living a life peace of mind and contentment.  Do nothing that tends to increase anxiety or fear or is in conflict with your conscience.