Bill C-18 (the so-called “Online News Act”), which is often referred to as the “link tax” bill, is very likely unconstitutional. There's been an excellent analysis of several reasons why this is the case by Konrad von Finckenstein and Phillip Palmer, whose joint and several expertise is quite formidable.
These learned authors mention copyright and seem to acknowledge a possible connection to copyright – but I would go farther and add one more potentially final nail to the C-18 constitutional coffin. This involves copyright law. I would contend that there is not and cannot be any possible connection to copyright law. The bill has a few references to copyright that are either ill-conceived or perhaps included as Machiavellian tethers to support some sort of connection to constitutional mooring. Absent any valid connection to copyright law, where is the federal jurisdiction to be found?
In Canada there is no copyright in a “title” or headline as such or a short snippet not comprising a “substantial part” of the article. Thus, the issue of fair dealing doesn’t even arise & the reference to the Copyright Act is a constitutional red herring.
Also, a hyperlink by itself is not “publication”. It’s just a modern and more convenient form of the traditional footnote. It is the fundamental raison d'être of the internet.
One of my very favorite copyright cases of all time is that of Francis, Day & Hunter Ltd. v. Twentieth Century Fox Corp. Ltd. et al., 1939 CanLII 276 (UK JCPC), a Privy Council decision from the legendary Lord Wright that involved alleged copyright infringement in Canada. In a nutshell, the case involved a movie entitled “The Man Who Broke The Bank At Monte Carlo” and a song written earlier with the same title. Other than the title, there was nothing in common between the two works. The Privy Council held that there cannot be copyright in a title because it is not a sufficiently substantial work of authorship.
The Privy Council also indicated that:
In this connection regard must be had to s. 3 of the Act of 1921 which defines copyright as the "right to produce or reproduce the work or any substantial part thereof." The definition (v) does not, in their Lordships' judgment, mean that the title of a work is to be deemed to be a separate and independent "work." Work is to include "the title thereof," that is to say, the title is to be treated as part of the work, provided that it is original and distinctive whatever these words may connote. When that definition is read with s. 3, the result is that to copy the title constitutes infringement only when what is copied is a substantial part of the work. This view would agree in effect with what was said by Jessel M.R. in Dick v. Yates (supra) in the words quoted above and would apply to a case such as a title covering a whole page of original matter, or something of that nature, but would not justify such a wide extension of copyright as the appellant company has contended for, or the holding of McEvoy J. on this point. It is said that so to construe the definition is to treat it as adding nothing to the law. But the definition may have been inserted to settle doubts and to avoid it being said that in no circumstances could a title receive protection. In any event their Lordships do not think that the new definition (y) entitles the appellants to succeed in this case.
(at p. 359 of report) (highlight and underline added)
Thus, any reliance on the notion that Google, or other Digital News Intermediaries (“DNIs”), are infringing copyright by reproducing the title (i.e. headline) of an article is ridiculous. The “Monte Carlo” decision is just as relevant to Canadian law today as it was 84 years ago.
Even the inclusion of a one or two sentence “snippet” from an article would presumably not entail application of the Copyright Act because it would likely not be a “substantial part” of the article and would thus not even need justification as fair dealing – which only is necessary if a “substantial part” is reproduced. Google News simply does not reproduce whole articles or substantial parts thereof. It long ago stopped providing even “snippets” and now just provides headlines.
Thus, the references in sections 23 to 26 to copyright are simply a red herring. The reference to the Copyright Board about a possible tariff is simply beyond absurd. Given the Boards historical inability to deal correctly with much simpler and more lucid legislative provisions, and its record of taking many years to decide cases and inevitably then retroactively and often wrongly, the notion of a Copyright Board “tariff” dealing with headlines of news articles is simply cringeworthy.
And, of course, links are no more than a modern and more convenient form of classical footnotes. The act of linking to an article without more is simply not “publication” and to legislate otherwise would threaten the very viability of the internet, as the SCC ruled a long time ago in 2011 SCC 47 (CanLII),  3 SCR 269:
 The Internet cannot, in short, provide access to information without hyperlinks. Limiting their usefulness by subjecting them to the traditional publication rule would have the effect of seriously restricting the flow of information and, as a result, freedom of expression. The potential “chill” in how the Internet functions could be devastating, since primary article authors would unlikely want to risk liability for linking to another article over whose changeable content they have no control. Given the core significance of the role of hyperlinking to the Internet, we risk impairing its whole functioning. Strict application of the publication rule in these circumstances would be like trying to fit a square archaic peg into the hexagonal hole of modernity.
(highlight and emphasis added)
The only reason to include the references to copyright in Bill C-18 was presumably to somehow tenuously tether it to a constitutional lynch pin. I would be dismayed if government officials were unaware of this fictitious foundation. Apparently, however, they are doing what officials tend to do – which is to try to rescue their Minister’s misguided and politically based missions and to get them across the finish line through Parliament.
If this should happen with Bill C-18, one hopes that Google would challenge it in the courts. However, Google’s policy strategies have become increasingly opaque in recent years. Moreover, its litigation strategy that effectively snatched defeat from the jaws of victory in the SCC in the 2017 in Equustek decision case was and remains very puzzling. See Google Inc. v. Equustek, 2017 SCC 34. Hopefully, Google will handle this and other possible constitutional issue issues, such as of whether it operates "a search engine or social media service, that is subject to the legislative authority of Parliament", more effectively than it dealt with the Equustek case in the SCC.
Although I am “not practicing law” these days, I would be willing to elaborate on the above in the Senate hearings as a policy provocateur if asked.