Nothing. What videoswiper is actually doing is it is massively adding embedded videos to your site using the embedded object codes from the source site. If videoswiper fell off the map, the videos that you have added would still function as normally.

The problem with videoswiper (as it currently exists... well, at least my problem with it) is that it does not actually transfer the video file. Rather, it just copies the embed code. This creates two problems for you:

1. If the source site shuts down, your videos go along with it.
2. If the source site deletes a video, the video no longer works on your site (you would not know that it wasn't working until you went to watch it).

On the positive side, by coping the embed codes, the video is not actually running from your site. Thus, you save tremendously on bandwidth.