Well they start asking for your email only, and after that they put you in the list for the future stellar Lumens airdrop. But at the end of the email, written with small characters, they say that they will airdrop stellar Lumens only to people who will compete the know your customer. In this case, it is very plausible that they will ask for your identification documents, passport or something similar. They might ileven ask for an utility bill, since this is not uncommon during Kyc process. So, I am not sure that this is just a personal information grab from blockchain
Com wallet team