Yeah I'll have to look into it more closely if it happens again. There was at least 24 backups of size 500Mb .. so 12 gb in backups alone. I reduced that to 12 for now, all backups are sent to Amazon S3 anyway.
The server specs were very minimal: 30Gb hard drive and 1 Gb ram, but i've now increased that a little bit.
But you're right, the data should be really small .. even with all the gifs I upload.