If files were routinely deleted after a short period it could equally suggest legitimate use - because it serves users who share legitimately for a short while, and enforces removal afterwards.[77] Much of the indictment, in the words of one analysis, "seems to be based on the simple assumption that encouraging more usage means they must be encouraging infringement", in other words there should be evidence of actual wrongdoing, not merely evidence of popular use. Many legitimate files are popular and popularly shared, and an assumption that paid use largely equates to infringing use would need evidence.[77] Failure to remove all links following a takedown request is often legitimate.