The first is the concept of spam. Spam as a concept is actually accredited to Montgomery Ward. That's right, you can blame them -- sorta. They came up with the concept of mail-order catalogs in 1872. Those catalogs were sent not only to people who were already customers, but anyone they could get a catalog to. Back before the days of the Internet, phones and snail mail were the efficient methods of ordering.
Fast forward 100 years, and we have the Internet. Sending bulk mail is no longer costly. I can do it electronically for fractions of a penny, instead of having to pay the heavy tax placed on that privilege by the post office. The only tax spammers have is the tax of getting connectivity, much of which they can steal. Which brings us to the second issue.AOL is credited to the origins of phishing. Yup, you can blame them -- sorta. In the early days of the Internet everything was dial-up, and AOL had a near monopoly on modem pools. While they hardly owned the Internet, they certainly dominated access to it for a short time and still do in many rural areas where broadband is just a distant glimmer of hope, unless you consider the latent dish a viable solution to broadband -- and you wouldn't if you've ever had to use it. But I digress.
AOL's dialup access was metered, unlike broadband. That is, you could only use it for a certain amount of hours per day, based on whatever you had pre-purchased. Of course you could purchase more hours, but you were only allotted a set amount for your base subscription. Enter a bad guy who wants to download porn movies that were multiple megabytes in size (huge back in those days) or chat about their new favorite band, and it may take hours. Hours that they need to stay online eat into their allotted hours that they purchased. Where their own lack of funds may thwart them, their ingenuity in stealing access from others prevails. Enter the dawn of phishing for credentials.
Now, looking back on the origins of these two curses of the Internet, it's an interesting exercise to think about what future signs might lead us to the conflicts and atrocities of the future. Here you can boil it down to the need to market goods and services (greed) and the scarcity of resources. It'd be interested in seeing if there is any predictive science that may ferret out problems before we inadvertently create them.