As I said on your site, I used to manage permissions for a university press, so I know the law, not only in the US but also in the UK. You are violating authors' intellectual property. From the US Copyright Office (emphasis added):

What Works Are Protected?
Copyright protects “original works of authorship” that are
fixed in a tangible form of expression. The fixation need not be directly perceptible so long as it may be communicated with the aid of a machine or device. Copyrightable works include the following categories:
1 literary works
2 musical works, including any accompanying words
3 dramatic works, including any accompanying music
4 pantomimes and choreographic works
5 pictorial, graphic, and sculptural works
6 motion pictures and other audiovisual works
7 sound recordings
8 architectural works
These categories should be viewed broadly. For example,
computer programs and most “compilations” may be registered as “literary works”; maps and architectural plans may be registered as “pictorial, graphic, and sculptural works.”

How to Secure a Copyright
Copyright Secured Automatically upon Creation
The way in which copyright protection is secured is frequently misunderstood. No publication or registration or other action in the Copyright Office is required to secure copyright.

Also from the US Copyright Office:
"Can I copyright my website?
The original authorship appearing on a website may be protected by copyright. This includes writings, artwork, photographs, and other forms of authorship protected by copyright."

You're wrong. And yes, you are a thief. Truth is a defense against the charge of slander!