There are elements out there in cyberland who are both criminal and on some kind of righteous crusade against what they have decided are bad pictures.
They have created a virus that is attached to certain individual pictures, which have been sent to various tumblr blogs and which, when clicked on, will infect your computer.
This virus takes over all operations and puts a page on your screen that says you are being investigated for child porn, and that you must pay a fine of $400 to avoid prosecution. It even gives you a helpful link to click on to pay this "fine."
Now think about that for a second. A Fine? For engaging in what is a felony? Paid anonymously, without any record of it? By an official Government agency? With a complete lack of due process?
Okay, so we know these people are criminals. What can you do about it?
Well, if you reboot your computer, it will come up to the welcome page just fine. Then try anything in the account you were using, and that page pops up again. You're stuck with it in that account.
So, if you run windows, and only surf from an account other than your administrator account, then all you have to do is reboot, get into your administrator account, and then delete the infected account. Problem solved.
If you were unwise enough to surf as the administrator, then you have just learned a very important lesson: Don't ever do that!
The only cure in that situation (that I'm aware of) is to take the computer to a professional and have them remove the virus the hard (and expensive) way.
Also, if you have any idea of which picture actually had this virus on it (assuming it is actually not a picture of an obviously underage person) then you might want to alert the Attorney General of the state in which you live that an extortion racket is being perpetrated by use of this website.
If they're really interested, they'll go after the site, and try to determine who is trying to collect this money and all that kind of thing.
This may be one reason that a number of tumblr sites seem to go mysteriously missing.
So, if you want to look at tumblr sites, which is your right under the law, and which is NOT illegal (assuming you're over 18) then you might want to do it from a guest account you create on your computer, and use only that guest account from now on.
Ain't life grand when others decide what you may and may not be allowed to do?
I'm really sorry if providing that link caused anybody any problems.