In most aspect-oriented languages, aspects have an unrestricted global view of computation. Several approaches for aspect scoping and more strongly encapsulated modules have been formulated to restrict this controversial power of aspects. This paper leverages the concept of programmable membranes of Boudol, Schmitt and Stefani, as a means to tame aspects by customizing the semantics of aspect weaving locally. Membranes have the potential to subsume previous proposals in a uniform framework. Because membranes give structure to computation, they enable flexible scoping of aspects; because they are programmable, they enable visibility and safety constraints, both for the advised program and for the aspects. The power and simplicity of membranes open interesting perspectives to unify multiple approaches that tackle the unrestricted power of aspects.