They could be doing any number of things but I think the general idea is that by keeping track of whatever it is they are tracking on the blockchain it would be

They could be doing any number of things but I think the general idea is that by keeping track of whatever it is they are tracking on the blockchain it would be impossible for them to modify the record after the fact. If they were keeping track of everything in a private database there is nothing except perhaps procedures they put in place from stopping someone from tampering with those records or the government accusing them of tampering with the records. Storing the records in the Bitcoin blockchain sort of puts them above reproach with regard to certain accusations.