Not to downplay anyone's trauma but I have had people find out...and they usually find it hilarious (let's be honest, it's TICKLING after all)!
Having parents see your search history as a kid is never fun but, as an adult:
There were a few instances with friends asking to borrow my computer. I was a bit careless (after all I'm a grown man with my own laptop/internet) so it wouldn't take them long to find some "breadcrumbs". It always garnered an eyebrow raise and a chuckle but that's about it.
Another time, I'd used my roommate's girlfriends Playstation 3 to save some clips (silly I know but they were in HD)! One day I came home to find the PS3 missing. Apparently they had broken up so she'd taken it back before I could delete anything. It wasn't until years later at a party that she drunkenly admitted she had watched the clips with her friends and they all found it hilarious (although she admitted a few scenes were "kinda sexy" to her).
As I've gotten older, I'm gotten sick of hiding things. Our fetish seems like a bigger deal to us than to other usually, I've found. For example, when dating this one lady, she wanted to discuss fantasies. She was so shy and blushy about admitting that she loved the feel of cold metal on her skin- but to me it was just like "oh! that's an interesting kink". I also immediately thought about my warternburg wheel... lol
I told her I wanted to tie her up and tickle her and she laughed like "oh! that's interesting!"
While I'm still generally a quiet person with this (it is a fetish for me after all) after realizing how many people find our fetish generally funny and entertaining, I don't feel too embarrassed about it.