This paper reports on an acceptability rating study of long wh-extraction from transitive and unaccusative subjects and objects in Hungarian, designed to test the predictions of competing etiologies of the islandhood of subjects. It is found that the (im)permeability of the three types of NP arguments tested is determined by their base position, and it remains unaffected by syntactic movement to a topic position. These findings cast doubt on the feasibility of monolithic accounts that propose to explain the islandhood of subjects as a case of ‘freezing by movement’, or as a case of ‘topic opacity’. Our results provide striking support for Chomsky’s (2008) phase-based approach to cyclicity, according to which licit wh-subextractions can proceed from the base copy of topicalized NPs, while constituents in phase edges, such as the occurrence of an external argument subject in the edge of vP, are impenetrable. We argue that in argument topicalization ‘topic opacity’ precludes subextractions from the occurrence of the argument in the topic position, but not from the copy in its base position. The general opacity of arguments undergoing topic fronting in English and German stems from the fact that in these languages a left-peripheral topic creates a topic-island for long subextractions launched from within the base copy of topicalized phrases.