How Did BBBH Get It's Name?

In February 2011 barebackers on Twitter decided they needed a short, unique hashtag for the bareback community. #BBBH was born at that point. For a more complete history check out one of the founder's recollection of how it all started. (He refers to 2010, but the tweets he links to are from 2011. Apparently the history was written some time later and backdated and he got the years wrong.)

Isn't barebacking dangerous?

Simple answer – No. Since the advent of PrEP (in about 2012) people who are at risk of HIV can stop themselves from getting HIV. The number of times PrEP has failed is extremely low. But even prior to the advent of PrEP we've known at least since the Swiss Statement in 2004 that undetectable poz guys can't transmit the virus. So there were ways to bareback safely even back then.

But what about other STIs?

Yes, STIs, other than HIV, are an issue when barebacking. That said, condoms aren't terribly effective at preventing some of the more common STIs, and no one thinks of oral sex as being all that risky, yet almost no one uses a condom for oral sex. So unless you're going to stop having sex, STIs are an issue no matter what type of sex you have. The important part is to get tested regularly so you can stop things from spreading.