Ancestry.com provides a forum for uploading and entering your information online. You have a choice of making your tree public or private. Individuals in private trees appear in searches but all details are hidden from the searcher until you grant access. This is not a collaborative site, e.g. others have read only access to your data and the ability to attach notes. You can upload and download GEDCOM files. People list view. Custom facts. Prompts for location. Can attach photographs and documents. Relationship calculator.
Cannot exclude living people without making the entire file private--of course one could upload two files and make the living people file private while making the deceased file public. No duplicate finder or manual merge ability. No bookmarks.
Search sometimes cannot find the people in your own file.
Free Ancestry Guest Registration is available at Ancestry Guest Registration.
If your tree is public then unauthorized access is not an issue.