Hey look yottabyte, you're in the news.

[Sebiale]

So they are basically building an incredibly oversized harddisk or solid state drive?

It's meant to store data, certainly.
The problem is that it's REAAAAALLY big so it can store A LOT of data, and they're attaining the ability to decipher any and all public information they can accumulate, which they can then use to track and graph anyone or anything.