Scathing open letter urges activist Bill Ackman to fix Chipotle's ‘grave failures' (CMG)

Chipotle investor CtW Investment Group has written a scathing letter to activist Bill Ackman urging him to fix the restaurant chain's "grave failures."
The letter, written by CtW executive director Dieter Waizenegger, casts doubt on Chipotle's sales recovery and accuses the company of failing to restore customer trust since the E. coli outbreak that sickened hundreds of customers last year. 
Chipotle's sales have fallen for three consecutive quarters since the outbreak. In the mos