SpeechSynthesis API may be fingerprintable
In https://bugzilla.mozilla.org/show_bug.cgi?id=525444, Mozilla landed support for JS access to OS provided speech synthesis. It appears to be off by default in FF24, but if it is enabled it may a fingerprinting vector through computer-specific speech packages which are exposed in an enumeratable fashion through speechSynthesis.getVoices().
We should keep an eye on this in case it gets enabled by default later.
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