Ughhhh my dad does this to me all the time.

He thinks it's hilarious.
The "screamers" don't get me usually because they have telltale signs most of the time.
1) They're short if it's a YouTube video.
2) They're a game that requires you to "turn the sound waaaay up!"
3) They require you to look at a picture for a few minutes looking for "something wrong with it"
4) The comments on a "screamer" video are usually along the lines of "OH man, that got me!!"
Although... one DID get me and a few others. We didn't notice the obvious signs and it didn't LOOK to be one because it was a video of a rocking chair that starts rocking on it's own. Then Reagan crawls from behind the chair. It got us because we saw the chair and we were like "Hm... that's eeri--AAAAAHHHHHHHH!!!"
Seriously... we were all on the sofa watching the same video... two guys jumped, I screamed, and the other guy screamed like a little girl and ducked under a blanket. I seriously wish we would have had a camera for our reactions

.