Flagging videos on Youtube?

Who the hell added these videos to my favourites folder on YouTube?

• I found several "favourited" videos in my YouTube account that were definitely not my or my partner's doing. What could have happened? Was I hacked? I recently accessed my favourites folder on YouTube and was startled to discover that 5 to 6 videos had been added to the folder without my knowledge. They were all related to Mighty Morphin Power Rangers, which none of us are interested in, and I believe my partner when he said he had nothing to do with it. He has his own YouTube account and isn't given to pranks in general. Possibly relevant details: 1. I am almost always signed in to YouTube because I only access the web through private devices (laptop, iPhone, iPad) that are not shared. 2. I used the iPad to watch videos on YouTube when we were in Shanghai and Tokyo in October. In Shanghai, we stayed at a luxury business hotel with free wi-fi that routed us through a VPN server in Hong Kong. We did not share the iPad with anyone else, and kept it locked up in the hotel safe when we went out. In Tokyo, we left the iPad charging on the desk in our hotel room once or twice. Unfortunately, I deleted the MMPR videos without checking to see if it was added when we were abroad. 3. Apart from the extra videos in my favourites channel, nothing else has been tampered with. No new videos have been added either. So... what happened here? Crossed lines? Hackers? Pixies? Hacker pixies? I'm not alarmed (yet), just very, very puzzled.

• Answer:

  Do those videos show up in your History on YouTube? (click on your username, one of the playlists is called "History". Of course now they might if you viewed them to see why they were in your favorites... (If so, it implies someone had access to either your device or your account cookie. If not, it is more likely to be a weird bug) Do you use http://support.google.com/accounts/bin/answer.py?hl=en&answer=180744 with your Google account? If not I recommend it anyway, whether anything shady happened or not, but it makes it much less likely (although does not protect against someone gaining physical access to a device you mark as trusted).