As requested: Buzzdock as Spyware
Now, I might be expanding the definition of 'spyware' beyond the modern definition, but going with the basic definition:
" ... collects information about users without their knowledge."
" ... software that monitors a user's computing ... "
Buzzdock is a layer that rewrites webpages with its own content, and tracks the user's search terms, pages, and information supplied to the sites visited. Source: Buzzdock.
They are also open about sharing your personal info with 3rd parties:
"In addition, the Company may share your personal information with our affiliated companies."
Now, I know Google might have similar terms, but the definition fits. And seeing that Buzzdock is an LLC and not a public company, there is less oversight over how your information is being used.
Yontoo as Malware
Buzzdock is built on top of Yontoo (source), which does have its own history of malware and spyware accusations here.
In addition, there are many complaints of Yontoo installing itself without the user's knowledge:
Spyware or Adware?
This might be the bigger question. How does one define the technical difference between the two given the interdependence of the data collection service to 3rd party advertisers?
Either way, as the OP suggests, and as others have claimed for 2 years, Yontoo installs itself without proper user awareness, rewrites webpages with its own content, and collects and passes on user information to third parties. Illegal? No. Worthy of a withering glare and a smack upside its head. Definitely yes. Security Threat? For the user to decide...