Well, delving into GridRepublic, have a look at the WCG Stats there and the possibility to switch between total and active. Think the latter are somewhat closer to the truth than those of e.g. BOINCstats that does not import anything beyond the first unique CPID for a project nor has hidden hosts included a.f.a.i.c.d (the sudden 100k device drop?). Some people do crunch with multiple accounts and lots by default are participating with host information hidden. Certainly can't find my device information being put into the host.gz file (uncompressed 700mb).