I think it is not necessary to download from you the whole blockchain. I don't know your intentions , they might be good but it is a security risk to download from another person the blockchain.
As long as you have a nice internet connection you can download the blockchain from your full node client i.e. Bitcoin Core.
peace
I had thought about it very seriously before uploading the database as well.
I am still a newbie in the subject.
I just think that the Bitcoin Core must be a very smart application, and it must thoroughly check the data directory before actually accepting it.
As for the speed, my home internet connection is very fast now but the blockchain downloading (syncing) was VERY slow. My download bandwidth was being used at 2-3% only.
But if there is a security risk, then maybe is there a Bitcoin Core command or something to validate all its database against the actual real blockchain?
I just want to really help speed up downloading, But I consider ANY SECURITY RISKS ABSOLUTELY UNACCEPTABLE HERE!!