Q. I am aware of the prohibition not to inquire about details or the price of a product or service simply out of curiosity and not because I want to buy it, because it will arose hope of a sale and then disappoint the owner when a purchase isn't made. Now that there are several community internet groups that help the community communicate about items for sale, advice, or events, I noticed that sometimes people inquire about an item or as to its price and later actually offer the same item for sale. Is it prohibited from inquiring about something for sale in a group where everyone is Jewish simply out of curiosity without intent to purchase or for the purpose of obtaining information to sell a similar item?
Is it prohibited to visit the website of a Jewish business to obtain information about a product that you intend to purchase elsewhere or sell yourself?
A. Horav Shlomo Miller's Shlit"a opinion is that commercial information posted on a public forum such as the Internet or a community publication, since it is open to all, it can be used as a source of data and knowledge for ones own personal benefit. However, that does not permit contacting them, either by phone or by email and misrepresenting oneself as a prospective customer, with the hidden intent of gleaning information to the detriment of the provider. This constitutes "Geneivas Da'as" or misleading people, and it applies equally to Jews or Gentiles (Chulin 94 a,b – Shulchan Oruch C.M. 228)
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit"a