Remember: the newly elected Trump named this guy his "cyberczar". This is why we need to mock people like Giuliani for their cyber-illiteracy.
2/ In case you were wondering what happened, Giuliani made a tweet where he forgot a space at the end of a sentence, leading one sentence ending in "G-20." and the next beginning with the word "In". Twitter sees this as "g-20.in" -- which looks like a domain name.
3/ So some jokester registered that domain and pointed it to a website with an anti-Trump message. This is in no way under Twitter's control and not something that Twitter is responsible for, yet Giuliani with his extensive cyberczar expertise believes it's Twitter's doing. 
4/ What twitter thinks is a domain name is automatic, so aisldfguhalksdfhu.in gets marked as a link by Twitter regardless of anything else. We humans can see "g-20.in" was a typo rather than hyperlink, but computers cannot see this.
5/ So why did "g-20.in" become a link and not "helsinki.either"? The answer is because ".in" is a top-level domain and ".either" isn't.
6/ You can get a list of current TLDs (top level domains) here at this link. You can also verify by typing combinations:
asdfasdf.work
asdfasdf.notwork
asdfasdf.blog
asdfasdf.foobar
en.wikipedia.org/wiki/Generic_t…
asdfasdf.work
asdfasdf.notwork
asdfasdf.blog
asdfasdf.foobar
en.wikipedia.org/wiki/Generic_t…
7/ Not only is Giuliani so bad at the cybers he doesn't understand this, he apparently doesn't know anybody good enough at the cybers who can explain it to him before he tweets about it displaying his ignorance to the world.
