I use to make an interface to send message to my website by using only HTML (without any kind of human verification). Annoying to get every days many fake message by bots that spam or flood my website, I do this interface by using Javascript : I mean, thanks fo JS, I open a box like a popup on my website, and than the message will be send using this interface.
After done this, I never get any kind of fake message. That I'd like to know : this is a real barrier to avoid the flooding on a website, or there are some kind of bots that can also use Javascript?
A bot can be coded to parse the javascript, of course, but most bots don't do this as they go for the easy targets.
If you'd really like to be safe, you need to implement something like a CAPTCHA, which uses images that are very hard to read by machines. But OCR has taken huge leaps forward, so they may be rendered useless in a couple of years.