Yes. The subtitles you create with the use of Amara will be visible to the general public and exposed to search engines. Other people will be able to play videos on Amara with your subtitles and download the subtitles to their computers.
Also, if the video you are subtitling is not part of a transcription / translation team (such as TED OTP team) and does not require special permissions for subtitling, other people will be able to improve your subtitles and translate them into other languages.
You can use Amara.org free of charge for subtitling and translating videos, so please do give back to the online community by letting other people enjoy your subtitles. Together, we can make videos more accessible to other viewers.
By submitting subtitles to Amara.org, you agree with Amara Terms of Service, so please make sure you have read Amara TOS and feel comfortable with them prior to submission.
If for personal, copyright, or commercial reason you absolutely need to keep your subtitles private, this may be arranged as part of Amara Pro services. Please check Amara Pro Web pages for details.