Phishing - is when the links come with a spam, clicking on which you are giving your personal information to scammers. It`s not always automatically, sometimes they ask you to enter some information and when you are entering it, the information is sending exactly to the scammers.
Tinyurl - is the service which allows to cut the links. Instead of a long and undistinguished you are getting short and nice. TinyURL.com was the first such kind of service, now they have business rivals. But TinyURL.com is still a leader, and it can be used by the scammers.
So, when you get the link TinyURL.com/M65G4 you will not notice at once, that it`s directs you to the personal page of the third level. What can be good on a such site? You would never go there. But thanks to the TinyURL there is such probability. The probability that you won't see the real link, will click on it. THAT`A WHY BE CAREFUL. HyipNews is warning you about the phishing with help of TinyURl, and other services of the short links! It`s really dangerous, be aware.