Here's what we know:
* He has a connection to the Baudelaire parents: Snicket knew the Baudelaire parents and even mentions that he was once "considered a possible guardian for the Baudelaire children," but ultimately, he didn't take on that role.
* He is on the run from an unnamed entity: He is pursued by a shadowy organization and is in constant danger, which is why he writes his stories from hiding. This suggests he might have been involved in some shady business or knows something dangerous.
* He has an ambiguous role in the events: His stories sometimes offer cryptic hints that he might be more than just an observer. Some fans theorize that he might be related to Count Olaf or that he was involved in the Baudelaire parents' mysterious disappearance.
Ultimately, Lemony Snicket's "crime" is that he knows too much about the Baudelaire orphans' tragic fate, and he is trying to warn others about the dangers of Count Olaf and the sinister world they inhabit. However, he also seems to be complicit in some of the events, adding a layer of complexity and mystery to his character.
In essence, the true nature of Lemony Snicket's "crime" is left intentionally ambiguous to keep readers engaged and pondering the mysteries surrounding the Baudelaire orphans' lives.