Each person have a different sequence, while the first time they sequenced one of the billions "human genomes". Doing different people could help finding what makes one person different from another and on the other hand what make us similar. :-)

While a single human genome is a lot of information, storing thousands shouldn't add much requirements, one can simply store a diff from the first.

Also, if they show interest in contacting us in the first place, they would probably value us as a source of information, so destroying earth would be counter-productive. Think on how much money is spent on making sure that our probes would not contaminate with earth life the places that it visits.

With glowing monkeys??? :-P

This is probably because no one uses it or care for it. Encryption is not a matter of simply slapping an encrypted channel on top of something and that something is magically secure.

Just on the top of my head I could bet that this telnet is vulnerable to timing attacks that ssh were once vulnerable. you see, telnet usually sends keys as fast as it can, so when you're typing your password the timing between the keys-down events are reflected on the timing of packages that go trough the net, with those timings you can narrow down the brute force password search.

SSH is more smart then telnet, so first it has a initial handshake that is not part of the session, so the first password, the login password, is sent in a single packet. But even for other password prompts that are asked during the session, openssh notice that the no-echo mode is activated and uses a timeout to join together more then one key on a single packet, since there is no echo this does not compromise the responsiveness of the session.