“we may collect information about your activities, like the apps you install or access (including usage statistics such as what apps you access, the time you access them, and how long you interact with them), and information about the videos and other content you select and stream within these streaming services.
When you use a smart TV with our operating system (e.g., a Roku TV model) with the Smart TV Experience enabled, we use Automatic Content Recognition (“ACR”) technology to collect information about what you watch or access (e.g., the programs, video games, ads and channels you viewed or accessed, and the date, time and duration of the viewing or access) via your TV’s antenna, cable box, game console, media player or other devices connected to your TV, and we may also collect additional information about the videos and other content you stream. The data collected while the Smart TV Experience is enabled may vary depending on your TV’s model and when you enabled the Smart TV Experience. For information specific to your TV, please see the Privacy > Smart TV Experience section of your TV’s settings menu. If you disable this setting on your TV, Roku will not use ACR on that TV, but Roku still receives information about your interactions and streaming activities on that TV through other methods.
If you use the Roku Media Player to view your video or photo files or listen to your music files, Roku will collect data about the files viewed within the Roku Media Player, such as codecs, and other metadata of the local files you play through the Roku Media Player”
My roommate, an iPhone user and English only speaker, left his TV on the Spanish channel with his phone right next to it and left for work. When he came back home and checked his phone, all his Facebook and Twitter ads were in Spanish. This was at least 10 years ago.