The bulk update request #8492 has been approved by @nonamethanks.
rename building_block -> toy_block
Frequently misused to such an extent that it's been removed from half the posts where it's been used. Taggers seem to assume that this tag is synonymous with building, which it isn't.
Wikipedia uses toy block for this purpose, which seems unambiguous enough. Our definition of this tag has always specified that they are toys, so putting "toy" in the tag's name shouldn't present a problem.