You could be linked to your clearnet identity through information that you provide about yourself, or through your writing style. It is surprisingly easy to link some people, if they have unique patterns or quirks in their writing style. One person on this forum was linked because he wrote "a lot" as "allot". That's a very unique way to misspell it, and I presume his spellchecker didn't catch it because "allot" is a real word. Generally, the more correct, normal and mundane you write, the harder it is to find signatures or "fingerprints" in your writing style, at least for amateur readers. Professional stylometrists might be able to perform statistical attacks on your writing, looking at things like word frequency, to match your anonymous and clearnet identities, but it's unlikely you have to worry about someone like that. No offense, but you do have a non-standard and non-correct writing style, so I would advise against it. JavaScript increases the attack surface against you, but I don't think Google is in the business of deanonymizing its users. The main reason being that a lot of people in censored countries use Tor and other proxies to access Google. Google wants them to access its sites. If it bugged its Flash video player on YouTube to connect over clearnet, the Iranian government could potentially see that connection. If someone was uploading a video of Iranian officials committing crimes, that could get them killed. Google can't take that chance, so I don't think they are in that game. Plus the general attitude that I've seen from people like Mike Hearn, a Google employee who has posted on the Tor mailing lists, is that they have no problem with anonymous users. The barrier to creating an account is mostly to stop spammers.