Critics of Supreme Court Chief Justice John Roberts' majority opinion that struck down overall limits on campaign contributions say he was wrong to assume the Internet is a sufficient substitute for government regulation.

Roberts, who wrote the Supreme Court's 5-4 decision in McCutcheon v. Federal Election Commission, suggested that the overall limits that wealthy donors can contribute to political campaigns should be lifted partly because increased transparency caused by the Internet is a solid safeguard against campaign-finance corruption.

"Today, given the Internet, disclosure offers much more robust protections against corruption" in elections, he wrote. "Because massive quantities of information can be accessed at the click of a mouse, disclosure is effective to a degree not possible" in past eras.

But government watchdog groups say that although the FEC makes campaign finance records available on its website, such disclosure alone isn't enough to thwart the potentially corruptive influence of big-money donors.

"Transparency does help neutralize the power of political cash," said Sheila Krumholz, executive director of the Center for Responsive Politics, which operates OpenSecrets.org, a nonpartisan website that tracks money in politics. "On the other hand, can disclosure replace regulation? I don't think so."

"I don't think transparency is equivalent to capping contributions. ... The two really are distinct."

Bob Lannon of the Sunlight Foundation said that because the FEC is short-staffed, it has a massive backlog of campaign finance records waiting to be uploaded onto its website.

He also argues that transparency laws don't do enough to reveal the source of "dark money" — political contributions given by groups or individuals to super PACs who don't have to disclose their identities.

"Transparency alone is not going to safeguard against the rise of a new robber baron class," he said. "To make the claim that [adequate] disclosure exists and will in any way ameliorate the bad consequences of this [Supreme Court] decision is either ignorant of reality or just careless."

Robert argued in his opinion that Americans have the right to contribute the legal maximum to as many candidates for congressional and presidential races, political parties and some political action committees as they want.

Federal law had said that during a two-year election cycle, individuals can't give more than $48,600 to all candidates for federal office or $74,600 to national party committees that make contributions to candidates.

With the ruling, individuals can give to as many candidates, parties or PACs as they wish, though the amount can't exceed the individual caps.

Roberts said the purpose of laws regulating campaign contributions should be to safeguard “quid pro quo” corruption, or when a contributor donates money in exchange for favors. And he suggested that by keeping in check the caps on how much each donation can be, corruption in politics will be stymied.

But David Earley, counsel with the Brennan Center for Justice's Democracy Program, said that's not enough to protect against those who try to illegally circumvent the system.

"Roberts is undoubtedly correct that disclosure today is better than it was," said Earley, who wrote an amicus brief in support of keeping the caps in place. But "there is no silver bullet, and you have to have a number of things working together to ensure that people can't get around the rules that you lay down to make sure the political process is not corrupted by those who spend money."

Meanwhile on Capitol Hill, Sen. Angus King, an independent from Maine, has filed legislation that would require all federal campaign contributions of $1,000 or more be filed with the FEC within 48 hours.

Under current law, only contributions made within 20 days before a federal election must be filed within 48 hours, with most others requiring filing on a quarterly basis.

"The American people deserve to know who is funding political activity — and they deserve to know in real-time, not months down the road," King said.