Neither USU nor the FBI responded to requests for comment on the status of the Sarkeesian investigation.
Last month, in an unrelated case, tweets implying that a shooting would occur, and picturing two handguns and ammunition, were directed at Brighton High School and its students.
Cottonwood Heights police converged on the school with bomb-sniffing dogs, and uniformed and plainclothes officers spent a week patrolling the campus. They didn't find anything, and Cottonwood Heights Sgt. Corbett Ford said he is skeptical they will ever find the perpetrator.
"They took steps to conceal their identity and hide their location, IP address — everything was anonymous," Ford said. He questions whether the suspect even lives in Utah.
Ford said he expects online threats will only grow as the Internet and online companies continue to offer perpetrators anonymity. Technological hurdles get in the way, and local police agencies only have so much time and resources to get past them. Plus, sometimes, the harassers, if caught, would face only misdemeanor charges.
It's the double-edged sword of online privacy: everyone wants it for themselves, but that same privacy can mire investigations, the sergeant said.
Investigators can flag a tweet or a text to keep a phone, website or social media company from losing it during routine memory wipes — if they are quick enough to flag it, since the wipes can occur within 24 hours. Companies tend to be quicker to act when the threat is against a large number of people, Ford said, "but again … we're talking hours and days as opposed to minutes." Interpersonal threats, including online bullying, can be hard for law enforcement to chase as well.
Private companies sometimes take a while to share customer information with the police, he said. He pointed out how a particular tech giant hasn't acted on one of the department's warrants issued months ago — citing an incorrectly written sentence in the warrant. Ford acknowledged that tech companies must get inundated with requests from law enforcement, but the result is that fulfilling any one of those requests can take a long time.
Further complicating police investigations is that some websites shield identifying information like IP addresses and physical locations, Ford said.
Tamara Denning, a University of Utah computer science professor, said people can use proxy servers, including servers in other countries, "so you start to get into different kinds of jurisdiction issues." She also described how some people use the Tor network, which passes messages along in several layers of encryption from server to server, so that its source is obscured.
"In some cases it is used for crime, but it is also used for getting around ... censorship and surveillance in some countries where that's in place," she said, adding that no technology is inherently bad.
It's possible to design "back doors" into programs for investigators to access private information, but that gets tricky.
"In some cases, we can try to design it so that it supports the good things but not the bad things, but that's a very difficult thing to do," Denning said. "Backdoors can be abused — not only if there are sort of regime changes, but just by people who aren't even affiliated with law enforcement."
Meanwhile, there are a growing number of avenues for messages to be sent anonymously. A year ago, parents condemned Ask.fm, another anonymous messaging website, for acting as a platform for bullying that led to a 14-year-old girl's suicide in England, according to London's Daily Mail. Despite the outrage, anonymous messaging programs continue to flourish.
Last month, threatening messages sent over Yik Yak — a year-old social media app that is all about posting anonymously — shut down high schools in California and Iowa, despite the company's attempts to prevent such abuse. But the negative press doesn't seem to be hurting Yik Yak's growing success, with the company valued between $300 million to $400 million, as of a large fundraiser held on Nov. 23, The Wall Street Journal reports.