A resposta é sim e não é mais necessário cookies:
Várias tecnologias existem para rastrear usuários, além de cookies. Alguma impressão digital de um navegador com base nas diferenças na renderização de cada site de um navegador, uma vez que cada navegador carregará a página ligeiramente diferente devido ao tamanho da tela, plugins, etc. A partir do Electronic Frontier Foundation :
ProPublica reported on new research by a team at KU Leuven and Princeton on canvas fingerprinting. One of the most intrusive users of the technology is a company called AddThis, who are employing it in “shadowing visitors to thousands of top websites, from WhiteHouse.gov to YouPorn.com.” Canvas fingerprinting allows sites to get even more identifying information than we had previously warned about with our Panopticlick fingerprinting experiment.
Canvas fingerprinting exploits the fact that different browsers have slightly different algorithms, parameters, and hardware for turning text into pictures on your screen (or more specifically, into an HTML 5 canvas object that the tracker can read). ... The main distinction is that the canvas fingerprint can’t be blocked by cookie management techniques, or erased with your other cookies. ...
E de Forbes
To combat the cookie’s flaws, advertisers and publishers are increasingly turning to something called fingerprinting. This technique allows a web site to look at the characteristics of a computer such as what plugins and software you have installed, the size of the screen, the time zone, fonts and other features of any particular machine. These form a unique signature just like random skin patterns on a finger. The Electronic Frontier Foundation has found that 94% of browsers that use Flash or Java – which enable key features in Internet browsing – had unique identities.
Fingerprinting may prove a more robust tracking technology than cookies because the user’s identity endures even if they erase their cookies. Making changes to your software and settings only makes you more identifiable, not less. An EFF study several years ago found that it is easy to track when someone changes their profiles by adding software updates, for example.
A Forbes também faz referência ao link do site da EFF para mostrar aos usuários quais informações os relatórios de seus navegadores podem usar para criar uma impressão digital única do navegador sem um cookie.
Finalmente, as operadoras de Internet introduziram suas próprias ferramentas de rastreamento, como o Cabeçalho Identificador Único da Verizon, conforme a Wired descreve O 'Perma-Cookie' da Verizon é uma máquina de matar a privacidade
Verizon Wireless has been subtly altering the web traffic of its wireless customers for the past two years, inserting a string of about 50 letters, numbers, and characters into data flowing between these customers and the websites they visit.
The company—one the country’s largest wireless carriers, providing cell phone service for about 123 million subscribers—calls this a Unique Identifier Header, or UIDH. It’s a kind of short-term serial number that advertisers can use to identify you on the web, and it’s the lynchpin of the company’s internet advertising program.
Cada uma dessas tecnologias fornece meios para rastrear, independentemente da presença de cookies e, no caso de injeção de cabeçalho UIDH, independentemente de qualquer configuração do navegador.