re: might
"They're the law, surely they should know if something is illegal or not!"
You'll obviously be somewhat surprised to find out that this assumption is not correct. It is widely assumed that law enforcement officials will be able to tell you if something is illegal or not, but, as ridiculous as it sounds, that is not the case. I once sent an email to my state's attorney general asking if online gambling was illegal according to my state's laws. The response I received was that he could not tell me, that I would have to seek advice from professional legal counsel. The state DA, the man who decides whether or not to prosecute criminal court cases, could not tell me if something was illegal or not. There's something wrong with your laws when law enforcement officials cannot tell you if something is illegal or not.
As for the confiscated items, I would venture a guess that, like in many other cases, they confiscated every piece of electronic kit in the room -- PCs, monitors, printers, scanners, keyboards, mice, speakers, storage media, phones, VCR/DVD players, VCR/DVD media, CD players and stereos, music CDs, televisions, etc. When executing seizures, they apparently don't believe in the word "overkill", even when something is clearly outside the scope of the search warrant (like confiscating a television).