The polyelectrolyte behavior of kinetically frozen multimolecular polystyrene-block-poly(methacrylic acid), PS-PMA, micelles has been studied in detail by a combination of light scattering, fluorescence correlation spectroscopy, and atomic force microscopy and by conductometry in aqueous solutions at low ionic strength. Experimental studies reveal important intermicellar electrostatic interactions. The experimental data are interpreted with help of computer studies, which combine mechanistic lattice Monte Carlo simulations and indirect treatment of electrostatic forces. The shell is modeled as a brush of self-avoiding chains tethered to the micellar core. Electrostatic interactions are obtained by solving the Poisson-Boltzmann equation.