Rainbow tables against Botnets?

[bitcoin2]

However, if the effective calculation of the coins would be a required a large amounts of data, this could prevent botnets. The rainbow tables could be sold on disks or be distributed in every major city (hotspots, wireless lan). Is the sha-2 algorithm too much salted to generate the coins faster?

[theymos]

All of the data that Bitcoin hashes is too large and random to use rainbow tables with.