does anyone ever find themselves wondering if a site is rigged?

There is a particular site I've been playing lately where no matter how I play I lose. I've won plenty of money playing on other sites, but this one site has me absolutely cringing every time I showdown. I have top pair, I get shown a set... I have a set, someone catches a straight... I have a straight, shown a flush...etc.

It's so bad that it's just reached a level of uncanny proportions.

Does anyone else ever wonder this, or is this just another example of variance?