T-Rex: A lot of things we do today are mediated by the computers on the internet!
T-Rex: So uh -

T-Rex: PROBABLY you should know how that works??

T-Rex: One of the first things you should know is NEVER TRUST THE USER. If you ask someone what their name is, you should assume 100% of the time they have not given you their name. Maybe it's a fake name. Maybe it's a racial epithet. Maybe it's code that'll mess things up if you display it while ASSUMING it's a name.
T-Rex: Assume EVERY SINGLE INPUT is hostile and toxic and must be sterilized.

Utahraptor: That's really how programmers think?
T-Rex: Oh hah hah hah! No. Not at all!

T-Rex: That's how SOME programmers think, but others think "okay, I've asked the user for their name and they've given me 400MB of data, I'll just shove this in our database and not worry about it" and then later you get a letter from your bank that says "We got hacked lol, who can say whose fault this is but it's not ours."

T-Rex: BUT it's how YOU should think when you get emails APPEARING to be from Bill Gates where he says he's got too much money and wants to give it to you, a complete stranger!
Off panel: Hah!
Off panel: After all our correspondence, William and I are HARDLY strangers