Open links from other applications in Private window

[reikoneko]

I would like Firefox to open any link that comes from another application (IRC, Discord, Steam, games, etc.) in a Private window. The current behavior is to create a new tab in my current main session, which could lead to privacy issues.

I don't want a plugin for this; I want it to be default behavior, or at least one that can be enabled in  about:config (separate from browser.privatebrowsing.autostart).

(This behavior also pairs well with the multiple suggestions asking for each private window having its own profile/context, e.g https://connect.mozilla.org/t5/ideas/allow-for-multiple-parallel-private-browsing-sessions/idi-p/176....)

[Jon]

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[myspace]

+1 want this 

[simon]

This is a good idea.

"I don't want a plugin for this; I want it to be default behavior," probably requires some explanation. Is this just about trust? Would a Mozilla vetted extension or maybe one provided by Mozilla be acceptable?