There are several such services, and some are potentially dangerous sources of malware, as they may not bother to protect or screen what users might upload. Anything one can web upload, is innately a more dangerous source of malware. Given it is the 800 pound Gorilla of videos, numbers of slimy users have commercial YouTube accounts, trying to figure out ways to abuse its intended design in order to extract money and information from users with free movies a lucrative starting point.
Common is bait and switch, where the advertised movie is not what the image or description actually shows. That is why I always look at Comments. Some B-grade movies have their titles changed in an attempt to trick users into thinking it may be something new, but only to find out a title has been changed, and other like sites for the same film, have even more different titles. Other free movies have so so so many ads that watching is unbearable, with breaks every 5 minutes where one has to Mouse select SKIP to avoid nauseating ads. Especially prevalent now, are all disgusting ED "Blue Pill" ads that have nothing to do with those with actual ED and instead are obviously targeting the epidemic of porn users.