It'll stop anyone unwilling to commit a breach of contract, which is a higher bar than "highest bidder can do whatever they like". Right now, most terms of service can be unilaterally changed by the company, which means the new owner can arbitrarily change them and then use the data however they like, without any contractual obligations binding them.
Right, and that's not going to be changing in a hurry. Stop giving people data that you don't want others to have.
If anybody who understands this issue says anything other than "Stop giving people data that you don't want others to have" then I have to question their judgement. If you do decide that something is incredibly valuable then hand over the data; but make sure you consider the data 'sold'.
