It wasn’t just Wikipedia that went dark today.

At least four Members of Congress “blacked out” their official websites in solidarity with an Internet-wide protest by opponents of bills to crack down on online piracy of music and movies.

Reps. Zoe Lofgren (D-Calif.), Earl Blumenauer (D-Ore.), Mike Honda (D-Calif.) and Anna Eshoo (D-Calif.) showed protest messages on their House.gov sites on the same day as websites such as link aggregator Reddit and online encyclopedia Wikipedia went dark over the Stop Online Piracy Act and the Protect IP Act.

“It’s inspiring to watch so many Internet users and creators stand up for the future of the Internet,” Lofgren said. “That is precisely what’s at stake in the battle over SOPA and PIPA.”

Other lawmakers also saw their websites go dark, though not on purpose.

With so much traffic being directed to Member websites through search engines such as Google and direct links from Wikipedia today, some pages were intermittently inaccessible.

Backed by the entertainment industry as a way to curb illicit posting of intellectual property such as movies and TV shows, the bills drew the ire of Silicon Valley, which argues they are too broadly written and could stifle innovation.

Like the online protest leaders she cited as inspiration, Lofgren encouraged visitors to contact their Members of Congress to express their concerns.

“If my colleagues in Congress hear about opposition to SOPA and PIPA from their constituents, I am confident that these bills will not become law,” she said. “If you care about online innovation and freedom of expression, call your Representative and Senators today.”

Visitors to her website were shown an all-black graphic with the words “Stop SOPA/PIPA,” but they could still click through to use the site normally. Eshoo and Honda had similar pop-ups.

Blumenauer’s website greeted visitors with a black screen and the message, “This site blacked out in solidarity with internet freedom.” The page also included the Congressman’s D.C. and district office contact information.

In a statement about the decision to black out his site, Blumenauer called SOPA and PIPA “misguided” and “overly broad.” “With jobs and free speech on the line, the stakes are too high for us to rush through broad legislation that does not meet our objectives,” he said.

According to the statement, the website was scheduled to be blacked out from noon to 1 p.m. PST.

Visitors to other House websites were sometimes given error messages today.

Dan Weiser, spokesman for the House Chief Administrative Officer, said the chamber’s Web server has experienced “an increase in Web traffic … which caused delays for some users.”

Although Weiser was unable to confirm a connection between the online protests and the at-times debilitating increase in traffic, the spike occurred as many protesting websites were encouraging visitors to contact their representatives in Congress.

Senate websites seemed to be experiencing similar delays. Although some websites appeared to be operating as normal, websites and contact forms belonging to PIPA supporters, such as Sen. Bob Corker (R–Tenn.), took longer than usual to load or did not load at all. The Senate Sergeant-at-Arms, whose office oversees Senate.gov websites, did not respond to requests for comment.

Emma Dumain contributed to this report.