Question: Someone uploaded an illegal "cracked" copy of a program to the internet. Is it permissible to download it?

Answer: There is an opinion that something made available over the internet is permissible to copy. This is based on the concept of zuto shel yam regarding hashavas aveidah. I.e., an item that has been swept away by a river or receding tide is considered ownerless, since there is no control over it and the owner abandons hope (yeiush). In the same way, once the program is made public on the internet, the owner has no control over it.

However, most authorities reject the comparison to zuto shel yam. There, the item is completely lost; here the creator still maintains ownership of his intellectual property and continues to sell legal copies of it. Furthermore, even the uploaded copy is not lost until people download it. In many cases, he can demand that the site remove the illegal copy.

Moreover, even in the case of zuto shel yam it is morally proper to return the washed away item to its owner, and, if the government demands so, is required halachically because of dina d'malchusa. (C.M. 259:7)