B777-200
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Landed As Precaution; General Declared Emergency; General Maintenance Action
Aircraft
Purser advised of unusual fumes in cabin.  I investigated and concurred that there were unusual; and  strong fumes that resembled burning plastic.  We accomplished the 'Smoke; Fire; Fumes' checklist. Since the condition continued; we followed the checklist's [direction] to land at the nearest suitable airport. We declared an emergency and diverted to ZZZZ for smoke and fumes in the cabin. Unusual event that was caused by a fan motor overheat.
Smoke was detected around door 2R by cabin crew.  Accomplished 'Smoke; Fire Fumes' checklist and declared emergency with ATC.  Landed at nearest suitable airport; with no evacuation needed; [then] made logbook entries.  Cabin crew did an outstanding job and cannot say enough about them.  We all worked together to the point I cannot think of one thing we should have done differently even looking back a day later.
B777 flight crew is informed of fumes in the cabin and the Captain; who was initially on break; investigates.  After running the smoke and fumes checklist the crew elects to divert to the nearest suitable airport.