Why does this taxi have 13 cellphones attached to its dashboard?

This is a taxi in Hong Kong, with 13 phones attached to its dashboard, some smart, some dumb. And believe it or not, there's a method to this madness.

One of the Reddit commenters says that most Hong Kong taxi drivers have "three to six dumb phones glued to the dash, plus a personal phone." They use them to queue dispatches from multiple taxi companies, keep track of fares and godknowswhatelse. This cabbie, however, must have taken that ride queuing system to a new level.