Exactly. Something being suspicious is about small differences from what's expected, differences that correlate with something bigger. Whether the disk is full of random data because it's encrypted or because it was securely wiped, either way it correlates with somebody having something they're working to hide.

Or a second-hand computer: I do not wish to carry previous owner's use history into my usage, and neither should anyone else. Do not conflate "unusual" with "therefore hiding stuff", and don't even try "hiding stuff, therefore bad".

There are legitimate reasons for wiping data...can't believe we're having this discussion, here of all places.

I agree there are legitimate reasons for doing so. None of which will matter to some official busybody rummaging through your drive. To them, a drive filled with random noise (instead of, say, being zeroed out) is going to be unusual in a way that correlates with bigger things they worry about. Or, in short, suspicious.

In no way am I arguing that you shouldn't wipe your data, use encrypted filesystems, or anything like that. That is a totally legitimate thing to do.

We're just talking about drawing attention to yourself from governmental agencies that probably don't have your well-being as their highest concern.

Using state-of-the-art encryption to keep your files safe is good. But if it leaves any evidence that you are indeed using encryption, you are potentially drawing attention to yourself. And people should be aware of that.

Suspicious, true. But in such case, you could be in trouble for refusing to provide the password to a suspected hidden drive which doesn't exist. How does that even make sense? (Rhetorical question)

From your point of view, it doesn't of course. You know that you don't have an encrypted partition.

But from the authorities' point of view, they will beat you until they're convinced you don't have anything of interest you can give up. That could last quite a while...

Which means that you can rot away for life, based on a LEO's hunch. And that's not The Sovereign People's Republic of Elbonia: that's Australia and the UK.