[dragontamer]

An interesting hack is to use a count-based bloom filter, maybe 8-bits per count instead of 1-bit.

As long as the "count" doesn't overflow to the max size (in this case: 255), you can always "remove" items from a Counting Bloom Filter. In effect, a traditional 1-bit bloom filter is simply a counting-bloom filter that "overflows" on the first hit.

If people really need deletion on their bloom filter, do realize it is possible! (as long as you select a proper bit-size).