First search "charlie chaplin development" or "charlie chaplin coding" on Twitter and filter by People.
You will find a user with the Twitter account: @ChaplinCoding
One of the posts says "Check out my other lists".
Twitter has a feature called Lists where users can create lists and other (logged in) users can view this.
In the second list entry by @ChaplinCoding, there will be the flag:
`uiuctf{pe@k_c0medy!}`