That story is misleading. Here's the original tweet (https://twitter.com/KBergCBS/status/219538999784652802) it's based off of:
"Atlanta has spoken with about 20 teams and is in at least a half dozen active discussions, source says. Nets/Joe Johnson one of many.
Translation: ATL has been in trade talks with 20 teams. At least half a dozen of those talks are still going on. Their trade talks with the Nets re: Joe Johnson are just one of many ongoing trade talks.
That doesn't necessarily mean they're actively talking to six different teams about Joe specifically.