Banks fined $549M after senior execs found texting on Signal, WhatsApp

It's not about "texting" but about

> Banks with employees covertly texting about official business on apps like Signal, WhatsApp, and iMessage have been caught red-handed. Now federal agencies are charging banks with violating laws requiring recordkeeping on all business matters.

Wait. So bank employees cannot use IM of any kind? Or they need a special kind of IM with audit log style integrity safeguarding mechanisms?