Double negatives are not used in Esperanto:

> Diru nenion al iu ajn!

> Don't say anything to anyone!

However, if you use two negative words, the meaning changes:


> Diru nenion al neniu!

> Don't say nothing to anyone! (= Say at least something to everyone)

However these kinds of sentences are very uncommon, and I'd rather assume the speaker made a mistake and intended the first meaning.