It's a big, vast universe and I believe aliens exist out there somewhere.  I'm a lot more skeptical when it comes to whether they've actually visited us.  

I mean, really, why would they come here?  To meet humans?  Why?  Humans are terrible.  I wouldn't want to meet humans if I wasn't one.  I am one and I still barely want to meet any humans.  It's a super long way even to the nearest star and, quite frankly, we're not worth traveling that far for.

More likely aliens would be interested in taking our resources, but we're doing a pretty bang up job of using all of those up quickly.  The amount of resources it would take them just to get here makes that seem like a cost-prohibitive venture.

On the other hand, I hear Bora Bora is pretty.  Maybe they just want to do a little sight-seeing?