|Larry Stylinson being super adorable. (source)|
I found out about fandom around 2002, when I was still a kid. Tumblr didn't exist yet, most of Harry Potter fandom lived on Livejournal and fanfic sites such as FictionAlley, and the way I found out about all this was via a newspaper article about fanfiction. So in my personal experience, without even having to do any research on the subject, I know for a fact that the mainstream press has been reporting about fandom for at least ten years. In recent years, fan culture has come into the mainstream in a big way, with entertainment news and gossip magazines regularly reporting at Comic-Con, and 50 Shades Of Grey topping all the bestseller lists for months. A lot of reporting on fanfiction/fandom is still pretty ignorant and disrespectful because most of the journalists aren't involved in fandom themselves, but fanfic isn't the secret society it was twenty years ago. And I'd find it vanishingly unlikely for anyone currently starring in a fandom-popular TV show or in a band like 1D to not be aware of fandom. In fact, I wouldn't be surprised if winners of reality shows like American Idol and X-Factor were actually briefed about RPF as part of their press training, just so they wouldn't alienate fans by seeming shocked or appalled by the concept.
|Patrick Stump replies to an RPS fan on Twitter. (source)|
Tumblr isn't private or "safe".
To me, the most confusing thing about the "what happens on Tumblr, stays on Tumblr" philosophy is the idea that Tumblr is remotely private, AT ALL. I was baffled when I noticed people complaining about their Tumblr posts being linked in the Daily Dot's 1D articles, not because I didn't understand the sentiment of being freaked out by the sudden publicity it gave to certain Tumblrs, but because I didn't understand how anyone could fail to realise that all Tumblr posts are public and insecure. Once you make a post on Tumblr, you're inviting other people to blog it. The platform is specifically designed to make it easy for people to spread information and pictures as quickly as possible, meaning that once you've posted something you have no control whatsoever over where it travels.
Think before you post personal information on Tumblr
I first noticed this trend for posting personal info just after I started writing my Avengers costume design posts. A bunch of people started following me on Tumblr all at once, and I was kinda curious who all these people were. The obvious answer was "Avengers fans", but I was alarmed to notice that a lot of the time when I clicked on a new follower's username, their Tumblr homepage would have a little blurb like, "Hi, I'm Katy, I live in Birmingham, Alabama, I'm 16 years old, I'm bisexual, and I love Avengers and Sherlock!" and then a photo. Perhaps as a person in my early twenties I already qualify as an old woman in some fandoms, but to me this kind of behaviour seems very dangerous, particularly on Tumblr where your profile is likely to be read by a lot of complete strangers.
A good way to look at this would be through a Sex Ed metaphor. Have fun with fandom, but make sure you always use protection unless you're absolutely prepared for the consequences. Take control of your personal info, and don't post anything in an easily-rebloggable setting like Tumblr or Twitter unless you're OK with anyone seeing it, because the internet gives people the opportunity to be infinitely more creepy than they are in real life. By and large, internet fandom is a great place where you can talk to the kind of geeky, awesome people you might not get to meet IRL (especially if you're still in school), but for every friend you make there are potentially hundreds of people silently passing through and looking at your Tumblr or Twitter without you ever knowing they're there.