SMS spread boycott day in Nigeria

According to reports, the National Association of GSM Subscribers of Nigeria and the Consumers Rights Project called for a one day boycott of GSM phone usage to try and reduce costs and increase coverage.

Local media reports suggested that the boycott also gathered notable support from consumers, and even from cellphone retailers, some of whom shut their shops on the day in protest. Not everyone observed the boycott, some businessmen saying that they could not afford to switch their phones off for the day.

Calls for the boycott were spread by a viral SMS, that read "Lets force GSM tariffs down. Join a mass protest: Switch off your GSM phone on Friday 19th 2003. They will lose millions. It worked in the US and Argentina. Spread this text"

I'm sure there was no such a thing in Argentina (and I've seen some e-mails calling for this action in Brazil, Spain and other places). Perhaps this was the first hoax that turned reality?