This study seeks to further the research on online language learning by examining the level at which intermediate ESL students understand and process sociopragmatic information in their second language (L2) in globally networked environments like Twitter. In this semester-long study, L2 English learners from a variety of first languages (Chinese, Spanish, Arabic) analyzed authentic English-language tweets produced by well-known native speakers, with a focus on abbreviations, hashtags and tweeter mood. Results revealed that high intermediate ESL students relied most heavily on word choice when making sense of English tweets, demonstrating that a majority were able to extract significant meaning from common abbreviations, prosified hashtags, indices of tweeter mood and the tweet's larger context. This investigation highlights Twitter's status as an authentic and dynamic L2 setting that facilitates the cultural enrichment of learners and enhances their socio-pragmatic awareness, while developing their multiliteracy skills in an L2.