Q. On question 3556 wrote that Horav Shlomo Miller's Shlit'a opinion is that there is no issue of using Whats-App when positive and helpful activities are involved such as for a group that engages in helping elderly or ill people or providing a minyan or attendants to a shiur by using that program. Would it be correct to provide some safeguards for that use?
A. Horav Shlomo Miller's Shlit'a opinion is that indeed it is recommended to have a reliable and trustworthy participant taking responsibility to watch over the actual activities of the group when they are constantly involved in communicating with each other, since they can easily degenerate to Lashon Hora or worse.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller, Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit'a