This study investigated the perception of pre-service science teachers on the effect of the ban on Twitter- use in Nigeria in building learning communities, linkages, and accessing information. While the ban was predicated on allegations of hijack of the microblogging site for negative activities, there were outcries of its impact on learners who use the microblogging site to garner information and build professional learning communities. Multistage sampling technique was used to select 114 final year pre-service science education teachers from two Universities out of which only 84 were Twitter users. This number became the sample for the study. A 20-item modified Likert scale questionnaire tagged "Pre-service Science Teachers' Perception of Effect of the Twitter ban on their community building" constructed by the researchers was used to collect data. The reliability of the instrument was found by Combach's alpha reliability coefficient to be 0.75. Results show that eighty-four (73.7%) of pre-service science teachers utilize Twitter for learning while 76% express the view that the ban has an effect on building learning community but this perception was not gender-related. The subjects claim to have been disconnected from their professional communities and linkages due to the ban. Suggestions were made for a policy review.