A U.S. appeals court struck down Net Neutrality rules governing online traffic Tuesday, raising concerns over the future of Internet access in the United States.

The United States Court of Appeals for the District of Columbia ruled against a 2010 order issued by the Federal Communications Commission establishing Net Neutrality.

Net Neutrality is the concept that all Internet data should be treated “neutrally” to ensure that information flows freely and indiscriminately. Basically, all websites would be treated equally – which has usually been the case -- with the goal being to prevent ISPs and governments from discriminating against or charging users differently for Internet access depending upon how they connect, where they're connecting from or what information they're trying to access.

In 2010, Reuters reported the FCC instituted rules banning the blocking of legal content and regulating how ISPs charged consumers for Internet usage, even while wireless carriers like Sprint were given more leeway to manage their networks. Net Neutrality advocates saw the FCC's adoption of the rules as a major victory.

But the FCC's new rules were met with legal challenges by the telecommunications industry, leading to an appellate court decision declaring Net Neutrality rules unnecessary partially because consumers can still choose what broadband Internet providers they use.

“[There] is no evidence in the record suggesting that broadband providers are carving up territory or avoiding head-to-head competition,” Judge Laurence Silberman wrote in his opinion. “At least anecdotally, the opposite seems to be true. Google has now entered the broadband market as a direct competitor.”

However, some Net Neutrality advocates fear for the future of the Internet and some consumers have expressed concern that popular services like Netflix may be hurt by the ruling.

Net Neutrality: Some arguments for and against

There are both upsides and downsides to Net Neutrality, as argued by supporters on each side.

Proponents of Net Neutrality fear that telecommunications companies are trying to impose a tiered service model on the Internet -- similar to how cable television subscriptions work -- where users would have to pay more to access certain kinds of websites. Proponents also worry that ISPs will engage in what some have called “double-dipping” where consumers pay for Internet access in the first place and are then are charged again based on what they do online. ISPs have also been accused of wanting to slow or cap network speeds and block online content from competitors while promoting their partners.

Opponents of Net Neutrality argue there are no such plans for a tiered access system and that the rules stifle innovation. They also argue that bandwidth is not infinite and that prioritizing some traffic is at times necessary. There’s also concern the rules could prevent ISPs from combating denial of service attacks perpetrated by hackers to take down websites. Some are simply opposed to government regulation of such a huge section of the U.S. economy.

Net Neutrality has been a contentious political issue and votes have usually been split down party lines, with Republicans often opposing the rules and Democrats usually supporting them.

How the ruling might affect you

ABC News recently posted a list of possible changes to the Internet in the court ruling’s aftermath:

1. Degraded service: If ISPs setup “fast lanes” for those who pay more for faster access, those not paying extra fees might experience slower Internet speeds.

2. Higher costs: Companies like Netflix, Hulu and other high-bandwidth enterprises may have to pay more to ISPs to ensure their services are accessible to customers, costs that might get passed on to the consumer. Some ISPs – like Comcast – have said they won’t do this, but there are no laws to prevent them from charging companies fees for higher bandwidth usage.

3. Decreasing innovation: "ISP fees will make it more expensive and harder to launch new services, especially for small companies not tied to existing players," Michael Weinberg, vice president at Public Knowledge, a digital advocacy group in Washington, D.C., told ABC News. "Ultimately, the Internet will look more like cable television -- with a handful of players and a high barrier to entry -- and less like the Internet as we know it today."

4. Uneven service: The ruling reportedly opens the door to ISPs forming partnerships with certain companies who would get their websites and services in a “fast lane” by paying more. Smaller content providers -- like a local news website or a blog -- unable to pay for faster access may find visitors leaving their websites due to slow load times.

5. An expanding digital divide: Big Internet services may not be the only ones potentially hit with additional fees by ISPs. "A child in a rural area who loses the ability to video conference with her physician specialist," said Tessie Guillermo, president and CEO of digital advocacy group ZeroDivide, told ABC News, "a single dad who can no longer take his online college courses or a community media outlet in the inner city that is charged more to distribute its news -- these are real losses."

What’s next?

The FCC still has some room to institute Net Neutrality rules after the court’s decision.

The court’s opinion defended the FCC’s power to regulate broadband providers, according to The Atlantic, Silbermann writing that "the FCC [has] virtually unlimited power to regulate the Internet."

The FCC could also choose to classify broadband providers as utilities like phones companies are, making them subject to "common carrier" rules that would ensure ISPs could not discriminate against certain types of online traffic and services.

Many eyes are watching how the FCC reacts to this court ruling and how the future of Net Neutrality unfolds in the coming months.