good you remind me, last time was already some months ago. But I think if someone deletes everything again, I will have to contact the Administrators anyway, I'm not going to make a backup twice a week...
The backup file I just created is 15 MB. It contains all entries to the databse (not only for bwmn, also for some other, smaller projects I did). Files like maps, pictures or the PHP files are not stored in the database, they take about 1 GB alltogether afaik. I'm not doing any backups on those, so LGI's maps are really gone now, except for the old versions that were overwritten before I updated the script.