The per-account write meter (PR #1151, [writes]) gives every account its own token buckets. A creator can make 100 accounts an hour ([tree] creates_per_hour) up to max_children, and each new child arrives with a full burst and its own hourly rate. So one leaked creator key can multiply the log's growth by its number of children: after ten hours of creates, 1,000 children at the default 4,600 operations an hour come to about 4.5 GiB of log an hour, enough to fill the default 2 GiB budget before a restart compacts it.
Needs write accounting that also charges an account's creator chain (or a per-subtree share of the budget), so one creator cannot stop every account's writes through its children. Related: 3mwvohnwn6g2r (checkpoint and trim at runtime) bounds history, but not genuinely new records.
Design for this and its sibling issue is in https://tangled.org/did:plc:swttlkbjvcoln67iievud7b3/pulls/1196 (plan/tree-quotas.md). It recommends charging each account tree's root, the one the proxy's in_flight_per_tree already counts, for writes, blob bytes and account slots, with no new stored state. Each share defaults to half its deployment total.