But the NSA itself eventually squashed the rumours, announcing officially that the issue was "an internal error that occurred during a scheduled update".
The site was apparently down for up to six hours on Friday afternoon and evening, indicating either a pretty serious error or some rather sluggish efforts at restoring normality.
The NSA has been increasingly beleaguered of late, with the ever-mushrooming Snowden leaks heaping embarrassment upon embarrassment.
With growing public distrust and distaste for the agency, it was inevitable that many would assume the outage was down to some sort of revenge attack by the internet community.
The incident also coincided nicely with a major rally in Washington D.C. over the weekend to protest against the NSA's snooping activities.
But of course, as the satirical science and technology cartoon XKCD pointed out in 2012, a public-facing website may be an easy target, but it's not really a particularly vital asset to a top-secret government agency.
It's unlikely that any of the NSA's spies were uploading deviously-obtained data to the site and ended up blocked from reporting Angela Merkel's latest text messages back to base.
On the other hand, the accidental outage seems to run counter to recent impressions that the NSA is overloaded with super-elite computer geniuses who can do just about anything, including breaking the most advanced cryptography.
At least, if those people are there, they're not working on the public website.
It also serves as a reminder that while updates are of course important, they should always be properly tested before being implemented in live environments, and proper known-working backups should always be available to fall back on in case of disaster.