Would I get in trouble for doing this? Are doing the same thing?

Generally, you should not use a name like "Sony" in your domain name.

All these big companies will trademark their brands and can easily seize your domain name if they so choose.

It's happened before that somebody started a fan site of sorts with the trademark in the domain name and the company actually loved it as somebody was essentially marketing for them, but most companies are, especially big ones, are not going to like this.

Companies like Amazon prohibit the use of trade marks in domain names. Some accounts were terminated for the violation of this rule.

Here is an article

Amazon Trademark Infringement, Ooopsss…

I think this rule is applicable not only for amazon trademarks but for all trade marks

Don't do it. Companies have the option of filing a UDRP proceeding to get back any domain you purchase that infringes upon their trademark.

ICANN | Uniform Domain-Name Dispute-Resolution Policy

"All registrars must follow the the Uniform Domain-Name Dispute-Resolution Policy (often referred to as the "UDRP"). Under the policy, most types of trademark-based domain-name disputes must be resolved by agreement, court action, or arbitration before a registrar will cancel, suspend, or transfer a domain name. Disputes alleged to arise from abusive registrations of domain names (for example, cybersquatting) may be addressed by expedited administrative proceedings that the holder of trademark rights initiates by filing a complaint with an approved dispute-resolution service provider.

To invoke the policy, a trademark owner should either (a) file a complaint in a court of proper jurisdiction against the domain-name holder (or where appropriate an in-rem action concerning the domain name) or (b) in cases of abusive registration submit a complaint to an approved dispute-resolution service provider (see below for a list and links)."

more details at link

When you infringe on someone's trademark, they do have the option to sue you if they want to, so it's not just a cease and desist that you may be looking at. It's just not worth the hassle of putting a site up to have it taken down or to get a lawsuit coming your way.