With Star Wars: The Force Awakens blowing up box office records like an implausibly vulnerable Death Star, it's no surprise that memorabilia featuring the autographs of the original films' stars can be hot commodities on the collectors' markets.

Unfortunately that also means people may end up paying top dollar for fake signatures. Mark Hamill is fighting the forgeries by verifying autographs sent to him by fans on his Twitter page.

"I'm so sorry there's so many fans spending their hard-earned money for fraudulent signatures," Hamill tweeted on Sunday in a message that confirmed a signature on a poster purporting to be his as fake.

He's responded to several fans posting images of autographs, both real and fake, over the week. "Use this example to judge any signatures you might contemplate buying in the future," Hamill wrote with one verified autograph.

Several include the hashtags #FightFraud, #BeatTheDealers and #FansRule. Hamill tweeted on Tuesday that from now on he'll "Like" tweets sent to him with real signatures.

Most of the images he retweeted are from Star Wars-related merchandise but he also included one of The Joker from Batman, who he's voiced in animated cartoons and video games since the 1990s.

Of note, he verified several autographs on vintage Star Wars cards that included some snarky notes that have gone viral online in recent months. Hamill wrote that the fan he signed them for wanted "extreme irreverence" and he was glad to oblige. "Never thought they'd go public," he added.

Star Wars Mark Hamill signature

One of the Star Wars cards featuring a signature and snarky line written by Mark Hamill that went viral online in 2015. (raggedrabbit on imgur)