Timestamp tweets against the Decred blockchain using dcrtime and ipfs! Just reply to the tweet you want timestamped mentioning @dcrtimestampbot.
Search by IPFS hash
How it works
Every time @dcrtimestampbot is mentioned on twitter, a hash of the JSON-like string of the entire thread is timestamped and a file containing this string is stored on IPFS.
Saving the IPFS hash you can get the thread digest and verify if it has been timestamped. This is a timestamp proof!