Hey there!
@kas made a post about cleaning up blobs from pub servers a while ago %xVgKaRs....

Blobs take up most data in my .ssb-folder and the @PicoPub - ssb-pub.picodevelopment.nl folder for that matter.

So basically there are message types out there called "blob", they contain a refference to a file. When your client loads and sees inline-links to these files it will try to fetch them for you (loading images) from anyone that is connected to you at that moment. After that they will be stored on your machine to be spread out to people reading that same message via you.

It needs to be said that some desktop clients (not sure which) as well as clients tailored to mobiles like ManyVerse and Tightbeam clean up blobs automatically. I've been online for well over 1.5 years now, followed a bunch of people and my desktop database sits at 8gb, so it's not actually that bad.

seequ it's possible to make a copy of your log which removes some feeds (people) from your history. It's not currently viable to remove a persons past history. There a new feed formats (for the persons message publishing) which moves all content of messages into blobs which means you can "delete" message content.