This study aims to reveal teachers' concerns on classroom practices of an elementary school where the Bring Your Own Device (BYOD) program had been implemented for years. Although BYOD has gained in popularity across the world and the possible educational benefits have been discussed thoroughly, little is known about the actual presence of personal devices in classroom after a number of years. The purpose of this study is to investigate why teachers who engaged in BYOD for years have reservations toward the BYOD programs. Drawing on an ethnographic study of one pioneer BYOD elementary school in Taiwan, this study details ways in which the sustainability of personal digital devices and related practices in classroom encountered great challenges from the teacher's perspective. In particular, borrowed from an Actor-Network Theory (ANT) framework, this study identified two types of reluctance: reluctance to be enrolled in and reluctance to be excluded respectively. These teachers' reluctance to accomplishing the needed assemblage resulted in reservations toward BYOD programs. The negotiated actions enacted by teachers' translation in order to maintain the unwelcomed network have important implications for BYOD policy stakeholders. This longitudinal study demonstrated a picture different from the novelty effect normally reported in BYOD literature.