Why did the FBI just tweet a flood of old documents about the Clintons?

After more than a year of silence, a verified Twitter account operated by the Federal Bureau of Investigation raised eyebrows last week when it suddenly awoke and fired off nearly two dozen links to its investigatory documents, some of which pertain to the current presidential candidates.

Left-wing publications and supporters of Democratic nominee Hillary Clinton questioned whether the FBI might have political motives in highlighting old case, just a week before Election Day, that scrutinize Mrs. Clinton, her husband, and their charitable foundation. The questions dovetail on complaints that FBI Director James Comey had already politicized himself and his bureau by telling Congress his investigation into Clinton's private email server might not be closed after all.

But officials and others contend the tweets were automated, disclosing only documentation made public in response to multiple Freedom of Information Act (FOIA) requests.

Jason Leopold, a senior investigative reporter with Vice News who sued the US Department of State for access to Clinton's emails, said in a tweet that the FBI's tweets are neither newsworthy nor scandalous.

Clinton campaign spokesman Brian Fallon had tweeted that the timing of the FBI's sudden flood of tweets was "odd" in the absence of a FOIA litigation deadline.

The FBI, however, says the tweets – under the FBI Records Vault handle – had been published pursuant to standard procedures, as The Guardian reported, publishing a statement from the bureau:

The FBI’s Records Management Division receives thousands of FOIA requests annually which are processed on a first in, first out (FIFO) basis. By law, FOIA materials that have been requested three or more times are posted electronically to the FBI’s public reading room shortly after they are processed.

Per the standard procedure for FOIA, these materials became available for release and were posted automatically and electronically to the FBI’s public reading room in accordance with the law and established procedures.

In addition to information about Clinton, the series of tweets – which began Oct. 30 at 3 a.m. Eastern time – included one collection of documents about Republican nominee Donald Trump's father, Fred Trump, described as "a real estate developer and philanthropist." The tweet that drew the most attention, though, was the most recent, concerning a closed investigation into former President Bill Clinton's decision to pardon fugitive financier Marc Rich, as The Christian Science Monitor reported last week:

The newly released documents pertain to a federal investigation into Mr. Clinton’s pardon at the end of his administration of Mr. Rich. Rich was [indicted] in 1983, evaded prosecution in Switzerland, and died in 2013. The files briefly cite the Clinton Foundation in connection with a larger donation in support of Clinton’s presidential library. The bureau appeared to be interested in a New York dinner in which the Rich pardon may have been discussed. But the investigation did not lead to federal charges, and the case was closed in 2005. ... 

The Clinton campaign responded by accusing the bureau of unfairly publicizing its inquiry into Clinton’s email practices while not revealing its probes into Trump. The FBI opened a preliminary inquiry into allegations Trump or his associates might have had dealings with Russian people or business under US or international sanctions. The bureau found no evidence to warrant a full investigation, sources familiar with the matter told Reuters.

While allegations of political motivations behind every action are common so close to a major election, Sean Gallagher wrote for Ars Technica that the more than 20 tweets could have been backlogged since June due to a simple website glitch that went unfixed until last week.