The government has had a system set up to read every packet of data traffic on the Internet since the FIRST day DARPANET's interconnection project went live. This is due to the technical need to recieve every packet, read every packet, decode the IP address in the header of every packet, process the IP address and then transmit the packet. People are very peripheral to this entire technical-level equation. Sure, some people see some raw packets every day, but most do not. Nonetheless, for all practical purposes every message is read in its entirity by government machines and never seen by humans.
Early Carnivore software might have just flashed a message that IP XXX had transmitted a message with the keyword "bomb" in it. The human might just see the IP address and the keyword, for all that you know.
And hey, you admitted that it doesn't bother you for machines to read and process public messages (this is actually MANDATORY for the Internet to even work in the first place, after all), so it really isn't an issue what those machines do with those messages, right?!
Yes, it is an issue.