Check the link I gave above. Get to learn those file sizes & the ways spammers name their files.
LW is not useless if you know how to avoid spam.
For videos, always check them first with Bitzi;
How to use Bitzi Web Lookup. People report whether video files are good or bad, etc. So this is a valuable way of checking if videos are ok before you download them.
For LW 5, check post #6 in that link.