Is adding "Flag as inappropriate" button necessary for site with expiring content?

I am not sure if this is the right place to ask but we have an interesting situation going on.

We are making a web service that allows users to share files, however, they do not have to sign up and the files are only kept for 2 weeks, i.e, the files will automatically expire after 2 weeks.

My question is, many content and file sharing sites have "Flag as inappropriate" button, which users can click to report a file that is violating the guidelines or file a copyright complain. However, these sites also require users to sign up before using, therefore it makes sense for the website to ban the user whose files have been flagged.

In our situation, users don't have to sign up & files automatically expire after 2 weeks, do we still put up the "Flag as inappropriate" button?

The only situation I can think of is when a user posts a file to a public forum, flagging a file will help us take it down quickly.