[slitaz]

Proper English should have been: "Facebook may track your browsing even after...".

The judge can rule about lawfulness, otherwise it looks like they are a investigative reporter that just found out about the technical capability to track users in such a way.

[lucb1e]

Oh, thanks, now I finally understand the title. Should be "may" or "It's legal to..." indeed.

[fareesh]

Was confused about the headline as well, made it seem like this was uncovered by the judge during the course of some trial.

[alangpierce]

Interesting. For me, it's normal and understandable to use "can" to mean "is allowed to". I certainly know and understand the word "may", and I've heard it's technically more correct, but it feels a little antiquated or overly-formal, so I tend to not use it in conversation but might use it in writing.

One source that "can" is ok here: https://en.oxforddictionaries.com/usage/can-or-may

I didn't realize that this use of "can" is something that would cause confusion. Maybe there's a regional difference? I'm from the western United States.

[dang]

I tried s/can/may/ above but it sounds archaic to my ear. It may be proper English but if it's fallen out of common usage, putting it up would be distracting too.