  Experimental tests of Bell inequalities ought to take into account all
detection events. If the latter are postselected, and only some of these events
are included in the statistical analysis, a Bell inequality may be violated,
even by purely classical correlations. The paradoxical properties of Werner
states, recently pointed out by Popescu, can be explained as the result of a
postselection of the detection events, or, equivalently, as due to the
preparation of a new state by means of a nonlocal process.
