Avoid leaky links: don’t reveal your research

By Sancho McCann ·

URLs should be as plain as possible

Uniform re­source lo­ca­tors (URLs) have been used since the ear­ly 1990s to spec­i­fy des­ti­na­tions on the in­ter­net. If you look or scroll up, you’ll see this page’s URL:

https://san­chom.github.io/leaky-links.html

These are some­times just called ad­dress­es. When click­able, these are called links or hy­per­links.

It has also long been ac­cept­ed, and in­creas­ing­ly ex­pect­ed, to pro­vide URLs, of­ten via a click­able link, in court doc­u­ments. For ex­am­ple, the December 2023 Amended Consolidated General Practice Guidelines of the Federal Court al­lows you to avoid filing a book of au­thor­i­ties (a doc­u­ment with a copy of each case cit­ed to) if you in­stead in­clude hy­per­links for all cas­es that are cit­ed in the mem­o­ran­dum of ar­gu­ment.

Judges and coun­sel of­ten in­clude URLs in their writ­ting when re­fer­ring to ma­te­r­i­al that is avail­able on­line.

A URL can inadvertently reveal much more

The URL can spec­i­fy more than just the des­ti­na­tion site and page. Often, URLs em­bed track­ing in­for­ma­tion. Below is a URL to a Youtube video. Everything af­ter the ques­tion mark is un­nec­es­sary and is like­ly a track­ing ID that re­veals to Youtube that this is a link that I have shared with you.

https://youtu.be/Bv5T4-L4gfU?si=1MdmEOw****I1fX-

A URL point­ing to a case on CanLII may share de­tails of the search that you used:

https://www.can­lii.org/en/qc/qccs/doc/2023/2023qccs1167/2023qccs1167.html?re­sul­tId=83ef81272f16479b9e9ae36de88447c9&searchId=2024-09-15T20:49:40:016/f484cd9df4cf466593e6a022129a8ac9&searchUrl­Hash=AAAAAQAVVVJMIHByaXZhY3kgcHJpdml­sZWd­lAAAAAAE

Clicking on the above link doesn’t just take you to 2023 QCCS 1167. It also will re­veal that I had got there by search­ing for the terms “URL,” “pri­va­cy,” and “priv­i­lege.”

A rel­a­tive­ly new brows­er func­tion that re­lies on in­for­ma­tion in a URL is called a “text frag­ment.” A text frag­ment in a URL will look like this:

#:~:text=[…]

When a text frag­ment is in a URL, mod­ern browsers will au­to­mat­i­cal­ly scroll to and high­light the specified con­tent at the des­ti­na­tion page.

For ex­am­ple, if you click on this link, many mod­ern browsers (not Firefox, yet) will take you to back to this page, but with a specified piece of text high­light­ed. Google’s search re­sults will some­times link to a page us­ing a text frag­ment to high­light ma­te­r­i­al as­so­ci­at­ed with the search that brought you there. The risk is that if you share that URL, it may re­veal in­for­ma­tion about your search. Footnote 1 in R. v. Dick, 2024 BCCA 272 in­cludes a URL with a text frag­ment. In that case, the high­light­ed text frag­ment ac­tu­al­ly seems apt to the pur­pose of the ci­ta­tion.

I have also seen peo­ple ac­ci­den­tal­ly link to a URL that points to a lo­ca­tion on the com­put­er they hap­pened to be work­ing on at the time, in­stead of to a lo­ca­tion on the Internet. This can po­ten­tial­ly even re­veal in­for­ma­tion pro­tect­ed by so­lic­i­tor–client priv­i­lege or re­veal that a ghost­writer was used. E.g. some­thing like:

C:\MYFILES\mé­moires\[NAME OF COUNSEL]\[NAME OF CLIENT]\...

The above ex­am­ples are to show the ways you might ac­ci­den­tal­ly share more in­for­ma­tion than you in­tend to share when you link us­ing a URL: track­ing IDs, ex­plic­it search query in­for­ma­tion, or hints about how you got to the page, and more.

Keeping your URLs clean

Here are some best prac­tices to keep your URLs clean, and to avoid leak­ing in­for­ma­tion you’d rather not share:

Notes

1. ↑ Certainly, there is a way to copy from the ad­dress bar safe­ly (i.e. copy only as far as the .html). But if as a rule you don’t copy from the ad­dress bar, you will not risk copy­ing too much in­for­ma­tion.