[Aizawa's weakness is showing, that is, in his world hero work and detective work are... pretty separate. The police may ask for a hero's help in certain cases but usually the most detecting they did was "where will they strike next?"]

The message from earlier also said distrust would spread among us.

["knowing it might be there"... would it be there watching? or would it be there in the person itself?]

... maybe the rest of the writing was purposefully damaged. They don't want us to know too much.

[After all, if no one could be trusted, anything written normally was just evidence to be destroyed.]