Believe it or not astronomers have only detected these within the last few years.  This is a bit more on the background of FBRs and their history:

FRBs have puzzled astronomers since they were first detected in 2007. This event, known as theLorimer Burst, lasted a mere five milliseconds and appeared to be coming from a location near theLarge Magellanic Cloud, billions of light years away. Since that time, a total of 16 FRBs have been detected.

Another possibility which is making the rounds is that this signal is not natural in origin. Since their discovery, FRBs and other “transient signals” – i.e. seemingly random and temporary signals – from the Universe have been the subject of speculation.

For example, in 1967, after receiving a strange reading from a radio array in a Cambridge field, astrophysicist Jocelyn Bell Burnell and her team considered the possibility that what they were seeing was an alien message. This would later be shown to be incorrect – it was, in fact, the first discovery of a pulsar. However, the possibility these signals are alien in origin has remained fixed in the public (and scientific) imagination.

Here is a theory.  Could these be related to that “dyson sphere” star everyone is talking about?  Could these be from similar stars in other areas, not just neutron stars?  Feel free to comment with your ideas.

thanks to universetoday.com for the great info