The shoe was on the other foot in Israel Friday -- Madonna performed a cover of Lady Gaga's hit song "Born This Way" ... the same song Madonna called a rip-off of her earlier work ... but it's unlikely this was an homage to L.G.

Madonna was rehearsing for a concert in Tel Aviv -- singing her own song "Express Yourself" -- then seamlessly transitioned into Lady Gaga's "Born This Way."

Madonna famously criticized "Born This Way" when it was released last year, calling the song a "wonderful redo" of "Express Yourself." Madonna then called it "reductive."

Gaga called Madonna's comments "retarded."

So we gotta ask ...

Lady Gaga is TERRIFIED Islamic hardliners might attack her concert in Indonesia, so she cancelled it ... this according to her reps.

Gaga's management team announced today there were major security concerns regarding the June 3 gig in Jakarta -- all because a few Islamic extremists were pissed about Gaga's risque costumes and dance moves, which they felt corrupted Muslim youths.

The Indonesian Council of Ulema chairman, Cholil Ridwan, fervently urged fellow Muslims not to attend the show, saying, "It's intended to destroy the nation's morality."

Security concerns for the concert skyrocketed from such beliefs, so much so the Jakarta police refused to issue the show a permit, even though 52,000 tickets had already been sold.

With a lack of permit, and the security threats, Gaga's team threw in the towel and decided to officially cancel today.

Gaga then released a statement Sunday via Twitter saying, "I'm so very sorry to the fans and just as devastated as you if not more. You are everything to me. I will try to put together something special for you. My love for Indonesia has only grown."

Here's "Judge Judy" star Judith Sheindlin, 69, in NYC on Wednesday (left) -- and cutting edge popstar Lady Gaga in Taiwan on Wednesday as well (right).

It ain't easy being green.

We're just sayin'.

Despite a photo that seems to say to the contrary ... Lady Gaga is NOT engaged ... sources close to the singer tell TMZ. 

Famed photog and close friend Terry Richardson posted a photo last night of Gaga sporting a huge rock with the caption, "Gaga showing off her new engagement ring!"

But our sources say it's just a ring and Gaga is not engaged to anyone.

It's unclear if Gaga is even dating anyone right now ... recent reports say she broke up with BF Taylor Kinney.

Famed celeb photographer Terry Richardson posted a photo of Lady Gaga last night ... sporting a giant rock he claims is her engagement ring.

Gaga herself has said nothing about the ring (and by "said" we mean "tweeted") and there are conflicting reports about her dating situation these days. Within the last two months, one story said her boyfriend Taylor Kinney was shopping for engagement rings ... another said they broke up.


A source close to Gaga tells TMZ she is NOT engaged.

The Russkies are pissed ... claiming a doomed Lady Gaga concert screwed them out of $1.5 million -- and now, they're taking it to court.

TV Service ZAO -- a media company that owns the Russian music network MUZ-TV -- filed the legal docs in Miami, claiming it paid the $1.5 mil to book Gaga for the upcoming MUZ-TV awards in June ... but the deal fell through ... and they still haven't gotten their money back.

According to the lawsuit, ZAO attempted to book Gaga through a Miami-based management firm called NWE -- which claimed it had the necessary Gaga connections to lock down the pop star for the summer appearance.

But ZAO claims NWE was just blowing smoke -- and ultimately failed to secure the singer.

ZAO claims it has repeatedly asked for its money back, but NWE has refused -- and worse ... siphoned off $300,000 from the 7-figure sum as a broker fee.

ZAO is suing for ALL its money back, plus damages. Calls to NWE have not been returned.

Lady Gaga's new boy toy -- "Vampire Diaries" star Taylor Kinney -- has already established the pec'ing order in his blossoming relationship ... shredding out hardcore in Southern California recently to soak up some rays.

He probably wasn't born this way.

In one of the first pics of the couple in public, Lady Gaga strolled with her hot new "Vampire Diaries" boyfriend Taylor Kinney in California recently.

The couple met on the set of Gaga's video for "You and I," where Kinney played her love interest.

So far no signs of a bad romance.

In what reads like one of the biggest sour grapes lawsuits of the year, Lady Gaga's former assistant claims she was a slave to the singer, having to do such unconscionable things as fetching a towel for her after she showered, and keeping GG on schedule!

Jennifer O'Neill says in her lawsuit ... she worked for Gaga for 13 months, and is owed $380,000 in overtime.  O'Neill says in her suit her job included "ensuring the promptness of a towel following a shower and serving as a personal alarm clock to keep [Gaga] on schedule."

O'Neill claims she had to cater to Gaga in "stadiums, private jets, fine hotel suites, yachts, ferries, trains and tour buses."

And, O'Neill says, she was required to be at Gaga's beck and call at her "earliest waking hour."

O'Neill is suing for the $380k -- which represents 7,168 hours of overtime during the 13 months.

Gaga is not a defendant.  O'Neill is suing Mermaid Touring Company, which Gaga uses for concerts and what not.

Gaga's rep told the New York Post the suit is "completely without merit."

Lady Gaga can pour Cheerios all over her wet, naked body as long as she wants -- the cereal company tells TMZ, the singer's controversial new music video is all just freedom of expression.

If you haven't seen Gaga's new video for "Marry the Night," you're missing out on 14 minutes of naked, avant-garde weirdness ... including a scene where she empties a box of cheerios on her naked body.

A rep for Cheerios tells us, the cereal company had nothing to do with the video -- but it also has no plans to pursue legal action.

The rep tells us, "We feel that people express their passion in a lot of different ways ... This was certainly a first!"

Probably the point, no?

Lady Gaga’s super high-cut dress at the International Emmys Monday night in NYC was this close to exposing her little monster -- but TMZ has learned, it wasn’t made that way. 

A rep for the designer -- Stéphane Rolland Haute Couture in France -- tells us, the asymmetrical frock came straight off the catwalk ... meaning it was intended to be worn by a model much taller than Gaga.

According to the rep, “The slit came way further up her waist than what our designers had in mind."

Despite the wardrobe malfunction, Stéphane Rolland insists, “We’re not mad that the dress ended up looking like that on Gaga ... she does make it a little naughtier!”