[tor-bugs] #7256 [Firefox Patch Issues]: Explore zoom-based alternatives to fixed window sizes

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#7256: Explore zoom-based alternatives to fixed window sizes
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     Reporter:  mikeperry            |      Owner:  mikeperry
         Type:  project              |     Status:  new
     Priority:  normal               |  Milestone:
    Component:  Firefox Patch        |    Version:
  Issues                             |   Keywords:  tbb-fingerprinting tbb-
   Resolution:                       |  bounty
Actual Points:                       |  Parent ID:
       Points:                       |
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Comment (by joebt):

 Now using TBB 3.5.2 (Windows).
 I see "odd" (unique) screen sizes reported / detected on browser test
 sites, in TWO scenarios.
 1) When Windows system DPI is set = default 96 DPI.
 2) When system DPI is NOT the default value (many users must set it
 larger, to be able to read screens. Ex.:  both Windows' & apps' Help
 screens, or text in browser screens (TBB).

 On browserspy.dk or others, with '''Windows' DPI = 96''', AND the TBB UI
 maximized (full screen), test sites don't show "common" screen (monitor)
 size.  They show something like 1920 x 927 - a very "odd" value.

 At same exact time, regular Fx shows "screen size" = '''1920 x 1080''' x
 24.

 If Windows' DPI is set > 96 (~ 100 - 110 DPI), screen size detected by
 test sites is very odd.  Then, with TBB UI maximized, test sites show
 something like 1647 x 661 x 24. An extremely UNIQUE value.

 TBB doesn't seem to report a believable, "common" screen size in either
 scenario:  when Windows' is set to default 96 DPI, or when it's set >
 default (say, 105 DPI), as millions of users must do, in order to read the
 screen - whether in a browser, other apps, help screens, etc.

 Comment #2 at  https://tor.stackexchange.com/questions/1619/fingerprint-
 effect-of-changing-tbb-default-font-size, '''"gacar's"''' comment
 indicates this whole issue may be more complicated than many realize;
 especially sites using "advanced" scripts to gather data (see link to
 "fpdetective" software, in the Stackexchange post).

 I'd imagine, that under all these quite common scenarios, a consistent,
 common screen size should be reported.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7256#comment:10>
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