We are in a modern world and it is important for us to know what the government is doing. Wikileaks give us the information that we are not allowed to see and it is important to take risks. I believe this is not harmless and it is a valuable source.
Wikileaks is a harmless source of information. When they were first introduced, Wikileaks was a big scandal about how they leaked confidental information. After awhile though, people got used to the company doing this and now they do not see them as a threat. Wikileaks is just one of those sites.
Despite WikiLeaks' claims that it is an journalistic organization they have a political agenda. They release and publish classified government information that reveals the names and locations of classified intelligence assets putting those agents at risk of death. Wikileaks as leaked information it knew was false in order to gain ongoing financial donations.
The question concerning Wikileaks is mainly do they have the right to release information that is contrary to a countires national security interests. The US gevernment has clearly taken the position that they do not believe so. A US soldier was at risk of being tried for treason for providing Wikileaks information. Not harmless, but there may still be a right to make the information public.
Julian Assange's WikiLeaks was a dangerous source of information, because it sought to disclose information that was never meant to go public. While the founder seems to think he was doing something good by making information public about hidden topics (like scientology and the NSA), what he did could have endangered people's lives. It's possible that WikiLeaks was also involved in hacking for information, which isn't legal.
I think that out of all the word choices I could use, "harmless" would not be one to describe the material on Wikileaks. Informative? Yes. Empowering? Yes. Dangerous? Yes, at least for the parts of world government that have been exposed for what they are. But I don't think I'd ever call it harmless.