  The origin and chemical composition of ultra high energy cosmic rays is still
an open question in astroparticle physics. The observed large-scale isotropy
and also direct composition measurements can be interpreted as an extragalactic
proton dominance above the ankle at about 10^10 GeV. Photopion production of
extragalactic protons in the cosmic microwave background predicts a cutoff at
about 5x10^10 GeV in conflict with excesses reported by some experiments. In
this report we will outline a recent statistical analysis (astro-ph/0506698) of
cosmic ray data using strongly interacting neutrinos as primaries for these
excesses.
