  Recent analysis of the combined data of cosmic microwave background, galaxy
clustering and supernovae type Ia observations have set strong constraints on
the equation of state parameter $w_X$. The upper bound $w_X < -0.82$ at 95%
c.l. rules out an important class of models, the domain walls ($-2/3 < w_X <
-1/3$). Here we revisit the issue of domain walls as a possible alternative to
the standard $\Lambda$-CDM model by questioning the assumptions made in the
choice of priors of the data analysis. The results of our investigation show
that domain walls can provide a good fit to the WMAP data for a different
choice of priors with ``lower'' values of the Hubble parameter ($h<0.65$), (as
indicated by Sunyaev-Zeldovich and time delays for gravitational lensing
observations), and ``higher'' values of the matter density ($\Omega_m > 0.35$),
(in agreement with recent measurements of the temperature-luminosity relation
of distant clusters observed with the XMM-Newton satellite). In this new
perspective, their existence would lead to important implications for the CMB
constraints on cosmological and inflationary parameters.
