That's fair, but the Referrer header already does that. It can be blocked, true, but either way this is just a single literal bit of data - I don't mind, but I see how someone might.
An argument could also be made, that this is beneficial to me, as if Amazon finds a lot of traffic from DDG, they might be more inclined to buy ad space with them, giving better funding to a service I like.
The HTTP Referer header is a horrible bug that should never have been part of the web IMO. When I tell laypeople that this happens they're often very surprised.
An argument could also be made, that this is beneficial to me, as if Amazon finds a lot of traffic from DDG, they might be more inclined to buy ad space with them, giving better funding to a service I like.