Pro's & Cons of URL Expiring Concept

Is there any disadvantage of using URL expiring concept to protect o开发者_JAVA技巧nline videos?

You're stopping your users from usefully bookmarking the URLs to get back to them later (thus, making life harder for your users), and stopping your users from mailing, tweeting or otherwise usefully sending the URLs of your best videos to their friends, so basically killing any chance that the videos may "go viral" and attract large number of viewers. In other words, you're working totally against the growing "social" component of the web world, as well as making your users' experience less pleasant and useful.

If you want to "protect" a URL e.g. against visits from users who aren't registered with your service, why not use the HTTP authentication mechanisms and/or cookies handled out and processed at application level in correspondence with registration and login? It seems to me that such approaches, if you do need protection, can have fewer issues than "expiring URLs".