San Francisco, April 8 -- Facebook Inc's WhatsApp tightened message forwarding limits on Tuesday, restricting users to sharing forwarded content one chat at a time after a jump in messages touting bogus medical advice since the start of the coronavirus crisis. The pandemic, which has killed more than 70,000 people worldwide, has been accompanied by what the World Health Organization (WHO) has called an "infodemic" of misinformation.p2...