>>9018378 (LB)
They are definitely from Twitter:
https://pbs.twimg.com/media/EXHvbz8XYAUTMTD?format=jpg&name=medium
https://pbs.twimg.com/media/EXHnCwPXgAI1p6f?format=jpg&name=medium
>Do you think that the famous "DOITQ" was a clever opportunistic usage of the twitter hash prefixes?
Very likely. They probably worked out Twitter's naming scheme very precisely and can pin down to the second when a given starting string will be given to uploaded images. It was a matter of timing.