Point the first: Liability. We're just here to record data for you and though we have an awesome resident fitness expert who will be glad to help you try to pick reasonable goals, you don't get to hold us responsible if you pick a stupid goal and injure yourself or whatever.
Point the second: Privacy. We're going to respect the privacy of your data; in other words, we won't whore out your email addresses or steal your identity or anything. We also won't share your data unless you explicitly ask us to. Though if you're really doing well, or have a unique goal that we think shows off Kibotzer in a cool way, we may beg you to let us show you off, like featuring your graph on the front page. In any case, your data is yours and we'll delete it at your request at any time. Otherwise, we reserve the right to anonymize your data and use it in the name of research.